Willow Family (Salicaceae). Fremont’s cottonwood is a native tree growing in riparian areas near streams, rivers and wetlands in the American Southwest. Fremont's cottonwood trees range from 12 to 35 meters in height, and trunk diameter ranges from 0.30 to 1.5 meters. The bark is smooth in younger trees, becoming deeply furrowed with whitish cracked bark with age. The leaves are cordate (heart-shaped) with white veins and coarse crenate-serrate teeth on the margins. The leaves have petioles 1/2 to equal the blade length, laterally compressed near the blade which causes the leaves to flutter in the wind. These trees are dioecious, with flowers in drooping catkins, which are 4 to 14 cm long. Cottonwoods bloom from March-April. The fruit is an achene, which is attached to a silky hair, en masse looking like patches of cotton hanging from the limbs, thus the name cottonwood. The seeds are wind dispersed.
Poplar, Alamo cottonwood
Regularity: Regularly occurring
Fremont cottonwood occurs in riparian habitats from western Texas west through New Mexico, Arizona, and California, northward into Nevada and Utah [49,82,92,97,104,108,120,128,139,162]. It also occurs in the Sonoran and Chihuahuan deserts of Mexico [88,128]. The Natural Resource Conservation Service's PLANTS database provides a distributional map of Fremont cottonwood and its infrataxa in the United States. Distribution by subspecies is as follows [73,82,108,162]:
Populus fremontii ssp. fremontii --- southwestern New Mexico westward through Arizona and California, extending north into southern and western Nevada, and southern and eastern Utah
P. f. ssp. mesetae --- southwestern and Trans-Pecos Texas to southwestern New Mexico and Arizona and extending south on the Central Plateau into northern Mexico
Fremont cottonwood does not occur in Colorado. Cottonwoods previously misidentified there as Fremont cottonwood have been reassigned as Rio Grande cottonwood (Populus deltoides var. wislizeni) [160,161].
Regional Distribution in the Western United States
This species can be found in the following regions of the western United States (according to the Bureau of Land Management classification of Physiographic Regions of the western United States):
BLM PHYSIOGRAPHIC REGIONS :
3 Southern Pacific Border
4 Sierra Mountains
6 Upper Basin and Range
7 Lower Basin and Range
12 Colorado Plateau
13 Rocky Mountain Piedmont
14 Great Plains
Occurrence in North America
For current distribution, please consult the Plant Profile page for this species on the PLANTS Web site. Populus fremontii is distributed throughout the Southwest, extending from California eastward to Nevada, Colorado, Arizona, Texas, New Mexico, and southward into Mexico. This species occurs throughout California and is most abundant in the San Joaquin and Sacramento Valleys. According to Hickman (1993), cottonwood occurs in alluvial bottomlands and streamsides at elevations less than 2000 m.
Fremont cottonwood is a native, deciduous hardwood tree [1,11,13,24,35,49,50,75] that ranges from 19.7 to 112 feet (6-34 m) [22,48,49,72,89,90,97,128,148,162] in height and has a broad, rounded or cylindrical crown [120,123]. The trunk diameter at breast height ranges from 19.7 inches to 12.8 feet (0.5-3.9 m) [22,48,49,61,72,90,97,128,148,162].
The bark is smooth on the trunk, twigs, and branches of young trees, but trunk bark becomes deeply furrowed at maturity [48,49,97,123,162]. Fremont cottonwood is dioecious [26,49,50], with small (approximately 0.04 inch (1 mm) in length), fragile seeds . The catkins range from 1.25 to 3.25 inches (3.75-8.26 cm) for the staminate and 4 to 5 inches (10.16-12.70 cm) for the pistillate . Fremont cottonwood is inundation and siltation tolerant . This tree has a lifespan of more than 130 years .
Catalog Number: US 1083326
Collection: Smithsonian Institution, National Museum of Natural History, Department of Botany
Verification Degree: Original publication and alleged type specimen examined
Preparation: Pressed specimen
Collector(s): M. E. Jones
Year Collected: 1882
Locality: Valley of Palms., Mexico, Central America
- Isotype: Sargent, C. S. 1919. Bot. Gaz. 67: 211.
Catalog Number: US 220707
Collection: Smithsonian Institution, National Museum of Natural History, Department of Botany
Verification Degree: Original publication and alleged type specimen examined
Preparation: Pressed specimen
Collector(s): M. E. Jones
Year Collected: 1882
Locality: Valley of Palms., Mexico, Central America
- Isotype: Sargent, C. S. 1919. Bot. Gaz. 67: 211.
Fremont cottonwood occurs in riparian communities throughout the Southwest and much of California [26,41]. It grows primarily on alluvial soil and on other sites where subsurface water is available during the growing season, such as near water tanks, along irrigation ditches, dry washes, floodplains of major rivers, large perennial streams, springs, and in desert oases [48,49,66,68,69,71,76,112,143,153]. Large, mature trees are generally found close to the main channel, while the seedlings and saplings are located on the widest parts of the floodplain [8,143].
Fremont cottonwood is found in areas where the annual range of temperatures is 9 to 67 degrees Fahrenheit (-5 to 37 oC) [25,35,40,83,86] and the majority of the annual precipitation occurs during the winter. Mean annual precipitation ranges for Fremont cottonwood are as follows [8,21,25,61,152]:
|AZ||12 to 18 inches (305-457 mm)|
|CA||1 to 4.5 inches (25.4-114.3 mm)|
|NV||9.2 inches (234 mm)|
|UT||8 to 11 inches (203-279 mm)|
Soils: Fremont cottonwood is found in alluvial valleys, on terraces of floodplains, stabilized gravel bars, and adjacent to disturbed sites (agricultural lands and forest clearings) [8,26,88]. Soil types and structures include well-drained, alluvial, sandy to sandy clay loams with varying degrees of organic matter [29,57], clay or other fine soil and rock deposits , coarse, rocky and sterile soils , and fine-grained alluvial substrates . It has also been described as fairly salt tolerant (< 1,500 mg/L) .
Elevational ranges for Fremont cottonwood are as follows:
|P. f. ssp. fremontii||References|
|AZ||2 to 9,428 feet (0.6-2,857 m)||[8,13,27,49,59,65,88,90,94,98,143,148,149]|
|CA||0 to 6,500 feet (0-1,981 m)||[7,31]|
|NM||789 to 9,428 feet (239-2,857 m)||[148,149]|
|NV||2,162 to 5,460 feet (659-1,664 m)||[9,21]|
|UT||2,494 to 6,103 feet (760-1,860 m)||[47,51,52,83,92,123,162]|
|P. f. ssp. mesetae|
|TX||2,600 to 4,800 feet (792-1,463 m)|||
Key Plant Community Associations
Fremont cottonwood can occur in pure stands but more often grows in association
with willows (Salix spp.), other trees, and shrubs [26,49]. Groves
of cottonwoods were used as an indicator of
water, especially in low desert areas, during the early exploration of the
western United States . Historically, Fremont cottonwood dominated many of the riparian
woodlands of the
Central Valley of California .
Published classification systems listing varieties of Fremont cottonwood as indicator species or as dominant components of community types or plant
associations are listed below.
Community ecology and distribution of California hardwood forests and woodlands
Forest and woodland habitat types (plant associations) of Arizona south of Mogollon
Rim and southwestern New Mexico 
Vegetation and soils of the Churchill Canyon Watershed 
Flora and vegetation of the Rincon Mountains 
Southwestern wetlands - their classification and characteristics 
Association types in the North Coast Ranges of California 
Riparian vegetation and flora of the Sacramento Valley 
A framework for plant community classification and conservation in Texas 
New Mexico vegetation: past, present, and future 
Classification of riparian vegetation 
Vegetation and community types of the Chihuahuan Desert 
Preliminary descriptions of the terrestrial natural communities of
Vegetation types of the San Bernardino Mountains 
Preliminary classification for the coniferous forest and woodland series of Arizona
and New Mexico 
Biotic communities in the sub-Mogollon region of the inland Southwest 
A series vegetation classification for Region 3 
Classification of riparian habitat in the Southwest 
A survey of riparian forest flora and fauna in California 
Desert grassland (riparian community in desert grassland region) 
Riparian forest and scrubland community types of Arizona and New Mexico 
Riparian habitat classification in the southwestern United States 
Plant communities of Texas (Series level) 
Vegetation of the Huachuca Mountains, Arizona 
Vegetation of the Santa Catalina Mountains, Arizona 
In Nevada, Fremont cottonwood is listed as a community
codominant with Goodding willow, with a basin big
sagebrush (Artemisia tridentata var. tridentata)-cheatgrass (Bromus tectorum)
In California riparian woodlands, Fremont cottonwood is
associated with northern California walnut (Juglans
hindsii) [19,80,112], coast live oak (Quercus agrifolia) , valley oak (Q. lobata) [19,54,80,110], Goodding willow
[28,65], sandbar willow (Salix exigua) , arroyo willow (S. lasiolepis) [28,121],
red willow (S. laevigata) [111,112,121], Oregon ash (Fraxinus latifolia)
[19,110,111,112], green ash (F. pennsylvanica) , white alder (Alnus
rhombifolia) [14,110,111,112,118], California sycamore (Platanus racemosa)
[14,19,67,110,118,125], box elder (Acer negundo)
[19,67,110], bigleaf maple (A. macrophyllum) , red alder
(Alnus rubra) , Arizona alder (A. oblongifolia) , Tecate cypress (Cupressus forbesii) , Russian-olive (Elaeagnus angustifolia)
, and saltcedar (Tamarix ramosissima) . Understory species include Oregon false goldenaster (Heterotheca oregona
var. oregona), California wild grape (Vitis californica) [19,80],
Douglas' sagewort (Artemisia douglasiana) [19,80], Pacific dewberry (Rubus vitifolius)
lemonade sumac (Rhus integrifolia), woolly bluecurls (Trichostema lanatum), wedgeleaf ceanothus (Ceanothus
toyon (Heteromeles arbutifolia), bush rue (Cneoridium dumosum),
hollyleaf cherry (Prunus ilicifolia) , rubber rabbitbrush (Chrysothamnus nauseosus),
Wood's rose (Rosa woodsii),
Torrey's saltbush (Atriplex torreyi) , common elderberry (Sambucus nigra ssp. canadensis), trailing blackberry (Rubus ursinus)
, California wildrose (Rosa californica) , and stretchberry (Forestiera
In New Mexico riparian woodlands, Fremont cottonwood is listed as
a codominant with
Goodding willow, sandbar willow, box elder, Arizona walnut (Juglans major), Arizona sycamore (Platanus
wrightii) [27,52,54,89], Arizona white oak (Quercus arizonica), Emory
oak (Q. emoryi) , green ash, velvet mesquite (Prosopis velutina), alligator juniper (Juniperus deppeana), catclaw acacia (Acacia greggii), saltcedar,
and box elder . Understory
species include stretchberry, desert false indigo (Amorpha fruticosa),
mule's fat (Baccharis salicifolia), screwbean mesquite (Prosopis pubescens),
arrowweed (Pluchea sericea)
[52,56,89], and western soapberry (Sapindus saponaria var. drummondii)
Riparian forests in Arizona consist of Fremont
black cottonwood , Goodding willow [27,75,83,88],
velvet ash (Fraxinus velutina) [83,113], Arizona sycamore
[27,83,88,92,113], Arizona walnut [27,88,92,113,116], box elder [27,116], green ash [27,88],
true pinyon (Pinus edulis)
, Emory oak, Ajo Mountain scrub oak (Quercus ajoensis), Bonpland's willow (S. bonplandiana)
, alligator juniper,
catclaw acacia, velvet mesquite , western honey mesquite, screwbean mesquite,
Athel tamarisk (Tamarix aphylla), saltcedar, and arroweed
[74,75,88]. Understory species include annual rabbitsfoot grass (Polypogon
monspeliensis), tree tobacco (Nicotiana glauca), Cleveland's tobacco
clevelandii), pricklyburr (Datura inoxia), giant Spanish needle (Palafoxia
arida var. gigantea), cattle saltbush (Atriplex polycarpa),
big saltbrush (A. lentiformis), fourwing saltbush (A. canescens), small coastal germander
cubense var. densum), coyote gourd (Cucurbita palmata), Thurber's sandpaper
plant (Petalonyx thurberi), spiny chloracantha (Chloracantha spinosa)
, mule's fat [75,88] and western soapberry .
In Utah, Fremont cottonwood, saltcedar, sandbar willow,
peachleaf willow (Salix amygdaloides), Russian-olive, saltgrass (Distichlis
spicata), and whorl-leaf watermilfoil (Myriophyllum verticillatum)
make up the lowland woody community
around Utah Lake. The understory consists of grasses and annuals or aquatic herbs
. Fremont cottonwood also occurs in Utah with Utah
juniper (Juniperus osteosperma) , water birch (Betula occidentalis), thinleaf
alder (Alnus incana ssp. tenuifolia),
red-osier dogwood (Cornus
Gambel oak, (Q. gambelii), box elder, bigtooth maple (A.
grandidentatum), narrowleaf cottonwood (Populus angustifolia), and lanceleaf cottonwood (P. × acuminata). Understory
species include chokecherry
(Prunus virginiana), Wood's rose (Rosa woodsii), thimbleberry (Rubus parviflorus),
Saskatoon serviceberry (Amelanchier alnifolia), northern black currant (Ribes
golden currant (R. aureum), blue wildrye (Elymus glaucus), fernleaf biscuitroot (Lomatium
repens), sweetcicely (Osmorhiza berteroi), Canada bluegrass (Poa compressa),
Kentucky bluegrass (P. pratensis), starry Solomon-seal (Maianthemum stellatum),
feathery false lily-of-the-valley (M. racemosum ssp. racemosum),
goldenrod (Solidago canadensis) .
Habitat: Rangeland Cover Types
This species is known to occur in association with the following Rangeland Cover Types (as classified by the Society for Range Management, SRM):
More info for the term: cover
SRM (RANGELAND) COVER TYPES :
202 Coast live oak woodland
203 Riparian woodland
211 Creosote bush scrub
303 Bluebunch wheatgrass-western wheatgrass
401 Basin big sagebrush
412 Juniper-pinyon woodland
413 Gambel oak
503 Arizona chaparral
504 Juniper-pinyon pine woodland
509 Transition between K031 and K037
Habitat: Cover Types
This species is known to occur in association with the following cover types (as classified by the Society of American Foresters):
More info for the term: cover
SAF COVER TYPES :
222 Black cottonwood-willow
240 Arizona cypress
255 California coast live oak
Habitat: Plant Associations
This species is known to occur in association with the following plant community types (as classified by Küchler 1964):
K023 Juniper-pinyon woodland
K027 Mesquite bosques
K030 California oakwoods
K031 Oak-juniper woodland
K032 Transition between K031 and K037
K037 Mountain-mahogany-oak scrub
K038 Great Basin sagebrush
K055 Sagebrush steppe
K057 Galleta-threeawn shrubsteppe
This species is known to occur in the following ecosystem types (as named by the U.S. Forest Service in their Forest and Range Ecosystem [FRES] Type classification):
FRES28 Western hardwoods
FRES30 Desert shrub
FRES34 Chaparral-mountain shrub
FRES40 Desert grasslands
Adaptation: Cottonwoods dominate the riparian forests of lower terrace deposits and stabilized gravel bars. Cottonwoods are found near water. They require a bare gravel or sand substrate with adequate moisture for germination and development. Cottonwoods grow very rapidly when their roots are in contact with the permanent water table; they can grow as much as 12 to 18 feet in 3 years.
In California, common associates are valley oak (Quercus lobata), interior live oak (Quercus wislizenii), California walnut (Juglans hindsii), and California sycamore (Platanus racemosa). Box elder (Acer negundo), Oregon ash (Fraxinus latifolia), alder (Alnus rhombifolia), and willow (Salix gooddingii, S. exigua, S. lasiandra, and S. laevigata) are particularly prevalent in the subcanopy. Understory species are mostly shrubs, including elderberry (Sambucus mexicana), buttonbush (Cephalanthus occidentalis), blackberry (Rubus spp), and California rose (Rosa californica). Lianas such as poison oak (Rhus diversiloba ) and California grape (Vitis californica are) are a dominant feature. Herbaceous vegetation is 1% cover except in openings where tall forbs may occur.
Typically, in California, cottonwoods and willows predominate on the immediate stream banks, whereas valley oaks are spread irregularly over the natural levees farther away from the river. In other parts of the American west, temporal gradients occur within a location in the riparian zone. Early pioneer communities such as cottonwood/willow give way to late successional communities such as mesquite or sagebrush, often a consequence of sediment accumulation (Patten 1998). Many similarities among western riparian ecosystems exist because several dominant genera (e.g. Populus and Salix spp.) are common throughout the West, and many geomorphic and hydrologic processes that influence riparian establishment are similar.
Western riparian ecosystems have been greatly altered by human activity. Riparian forests have been reduced to fragmented, discontinuous patches because of human intervention. For example, estimates are that 70 - 90 percent of the natural riparian ecosystems in the U.S. have been lost to human activities (Warner 1979). Regional losses in these ecosystems have been estimated to exceed 98% in the Sacramento Valley in California (Smith 1977) and 95% in Arizona (Warner 1979). Many factors have contributed to these resource losses, including the following: natural resource use; urbanization; alteration of stream flows through dam construction and ground-water withdrawal; modification of biotic conditions through grazing, agriculture, and introduction of non-native species; and alteration within watersheds (Patten 1998).
Restoration: Use of an ecosystem model of riparian restoration has been used to create a functioning and self-sustaining habitat. The long term objective is to create a framework within which natural selective forces can operate to create a self-sustaining, functioning riparian habitat that not only provides habitat for a complete assemblage of riparian species, but which is also capable of long-term regeneration and recovery following natural disturbances (Baird 1989). Careful design, monitoring, and adaptive management are key components to successful restoration. The structure and dynamics of the plant community as well as species composition are designed and monitored, as well as landscape position.
Live Plant Collections: Fremont's cottonwood is a pioneer or colonizing species and a prolific seed producer (Stromberg 1993). Fremont's cottonwood propagates primarily from seed rather than asexually. Cottonwood can also sprout shoots from lateral buds when the apical meristem is prostrated by floodwaters, snapped off in high winds, or pruned by beaver, deer, or other wildlife.
Flooding is the primary disturbance in Fremont's cottonwood forests. Seed germination and tree establishment coincides with flood events. Fremont's cottonwood seed germinates only during spring and early summer. This seasonal restriction is due to: 1) early spring seed dispersal; 2) short periods (1 to 5 weeks) of seed viability; and 3) rapid seed germination (Shafroth et al. 1998). These traits help synchronize germination with high stream flows in spring. Moist soil is necessary for both germination and establishment of Fremont's cottonwood.
During this century most of the major rivers in the West were dammed. The presence of these dams changed riparian habits in ways unfavorable to cottonwood regeneration. In particular, the dams altered the timing and volume of water flowing through riparian areas. The dams reduce floodplain inundation during spring, and spring flooding is necessary for cottonwood regeneration.
Spring over-bank flows or capillary wetting of the soil surface in areas with shallow water tables, moistens the soil which is necessary for Fremont's cottonwood establishment. A number of studies have related components of the reproductive cycle of Populus species to floodplain site conditions produced by stream flow and associated fluvial processes. In particular, components of the annual pattern of stream flow, or annual hydrograph, are associated with specific stages of Populus seedling emergence and growth. These include the following: 1) flood flows that precede Populus seed dispersal produce suitable germination sites; 2) flow recessions following a peak expose germination sites and promote seedling root elongation; and 3) base flows supply soil moisture to meet summer and winter seedling water demand (Shafroth et al. 1998; Mahoney et al. 1998). The combination of root growth and capillary fringe defines the successful recruitment band for seedling establishment, which is usually from about 0.6 to 2 m in elevation above the late summer stream stage (Mahoney et al. 1998). The rate of stream stage decline is also critical for seedling survival and should not exceed 2.5 cm per day .
Cottonwoods grow rapidly and can reach medium/large tree height in about 20 to 25 years. Cottonwood forests could occur as rapidly as 25 - 30 year (Grenfell 1988). Shrubby riparian willow thickets may last 15 to 20 years before being overtopped and shaded out by cottonwoods. Cottonwood or willow tree habitats close to river channels that receive a good silt infusion, without major disruptive flows, tend to be self- perpetuating.
Cottonwood is susceptible to mistletoe. In certain instances cottonwood can be invasive. Its shallow root system can disrupt sidewalks or pavement.
Artificial Establishment: Fremont's cottonwood establishment from seed is difficult and seldom used. Fremont's cottonwood propagation is possible from hardwood, root cuttings and through tissue culture (Pope et al. 1990). Fremont's cottonwood establishment from transplanted containerized saplings is costly and risky unless the saplings are irrigated. The NRCS Los Lunas Plant Materials Center, in cooperation with the U.S. Fish and Wildlife Service, developed a pole planting technique for establishing Fremont's cottonwood (USDA, NRCSa). We reprint this procedure below.
“Trial planting on well adapted sites indicate more that 80% survival of cottonwood and willow poles when dormant poles are cut and planted between November and February.
It is essential to monitor the water tables at proposed planting sites for at least one year before planting. Poles planted where the water table fluctuates widely will have lower survival rates than those planted where water table is relatively stable. If groundwater monitoring shows the water level will drop more than 3 feet during the growing season (May-October), another site should be selected. Monitoring of observation wells for at least one calendar year before planting will allow better planting depth to ensure establishment.
Salt cedar (Tamarix chinensis) and Arundo donax will need to be controlled before poles are planted. However, young cottonwoods and willows can grow successfully in quite small openings in stands of salt cedar. Study of natural stands suggest they will eventually shade out the salt cedar."
In six riparian restoration projects carried out in California, competition from exotic weed species was a key factor in mortality and site failure (Baird 1989). With the addition of water, weeds grew so vigorously that plants smaller than a 5-gallon pot was out-competed. One way to avoid this was to remove the surface soil, although this has the disadvantage of removing nutrients, mycorrhizal fungi, bacteria, and insect and invertebrate populations critical to a healthy habitat. They also used a cover crop of native wildflowers, hand-broadcast over the site to aid in weed control. On wetter, heavier soils this does not seem to provide effective weed control.
There is considerable evidence that fertilizing a restoration site in southern California favors exotic weeds over native plants (Grime and Hunt 1975; Grime 1978; t. John 1987 and 1988). Inoculation with mycorrhizal fungi enabled seedlings of some species to better utilize limited supplies of both water and nutrients. Baird (1989) achieved inoculation through large (1.2 m deep by 2.8 m wide) root balls of mature trees brought in from riparian sites. Smaller, more economical soil plugs scattered throughout the site serve the same purpose. The number of soil plugs needed to ensure the establishment of soil flora is directly related to the distance of the restoration site from a similar, mature community.
Fire Management Considerations
In the southwestern United States, many riparian areas have been invaded by saltcedar . Saltcedar-dominated communities accumulate fuels more rapidly than Fremont cottonwood-dominated communities and consequently burn about every 10 to 20 years [122,154]. Native vegetation, including Fremont cottonwood, is often absent from these burned areas despite prefire presence. The native vegetation is usually replaced by the fire-adapted saltcedar [33,99,122]. For the remaining Fremont cottonwood woodlands to survive, saltcedar needs to be removed and replaced with natural vegetation. Once this is done, a more natural fire regime can be reestablished .
Plant Response to Fire
Most cottonwoods (Populus spp.) readily coppice following an injury such as fire; Fremont cottonwood sprouts primarily from the bole [34,70,145]. This ability presumably depends on fire severity. Fremont cottonwood also sprouts from roots , but there is no fire-related documentation of this regeneration method. Sprouting ability of cottonwood species is reported to decline after 25 years of age . See black cottonwood for further information on sprouting response of Fremont and other cottonwoods.
Fremont cottonwood regenerates from off-site seeds if suitable site conditions exist during seed dispersal (see Botanical Characteristics, Regeneration Process).
Immediate Effect of Fire
Mature Fremont cottonwood trees are top-killed by moderate fire [2,5,14,15]. The cambium layer is damaged by even low-severity surface fire [143,154]. In California, a severe wildland fire completely consumed the understory vegetation of a Fremont cottonwood community. Fremont cottonwoods that were top-killed by the fire were sprouting vigorously from the root crowns .
POSTFIRE REGENERATION STRATEGY :
Tree with adventitious bud/root crown/soboliferous species root sucker
Initial off-site colonizer (off-site, initial community)
Fire adaptations: Fremont cottonwood sprouts after fire or other injury. Coppice sprouting is the predominant mechanism of vegetative reproduction in most areas. However, root suckering is the predominant method in some areas of Utah [34,70,79,91,145].
Disturbances such as fire may favor seedling regeneration. Fire thins the overstory and surrounding vegetation, allowing light to penetrate, and exposes mineral soil .
FIRE REGIMES: Fremont cottonwoods are not fire dependent . Historical FIRE REGIMES for Fremont cottonwood-dominated riparian zones bordering drier ecosystems are poorly described . Fire scars are rare on Fremont cottonwood and when found, usually have such extensive heartrot that the tree's fire history cannot be reconstructed [146,147].Wildland fires appear to have been infrequent in riparian communities dominated by Fremont cottonwood, Goodding willow, and mesquite species prior to invasion by saltcedar . FIRE REGIMES for plant communities and ecosystems bordering Fremont cottonwood communities are summarized below. For further information regarding FIRE REGIMES and fire ecology of communities and ecosystems where Fremont cottonwood is found, see the `Fire Ecology and Adaptations' section of the FEIS species summary for the plant community or ecosystem dominants listed below.
|Community or Ecosystem||Dominant Species||Fire Return Interval Range (years)|
|California chaparral||Adenostoma and/or Arctostaphylos spp.||< 35 to < 100|
|sagebrush steppe||Artemisia tridentata/Pseudoroegneria spicata||20-70 |
|basin big sagebrush||A. t. var. tridentata||12-43 |
|saltbush-greasewood||Atriplex confertifolia-Sarcobatus vermiculatus||<35 to <100|
|mountain-mahogany-Gambel oak scrub||Cercocarpus ledifolius-Quercus gambelii||<35 to <100|
|blackbrush||Coleogyne ramosissima||<35 to <100|
|California oakwoods||Quercus spp.||< 35|
|coast live oak||Quercus agrifolia|
|Arizona cypress||Cupressus arizonica|
|California steppe||Festuca-Danthonia spp.||< 35|
|desert grasslands||Bouteloua eriopoda and/or Pleuraphis mutica||5-100|
|galleta-threeawn shrubsteppe||Pleuraphis jamesii-Aristida purpurea||33]|
More info for the terms: climax, natural, succession
Fremont cottonwood is a shade-intolerant pioneer that typically establishes on freshly exposed alluvium, sand or gravel bars, streambanks, or other floodplain sites following winter/spring floods [26,79,80,111,112,143,144]. Communities dominated or codominated by Fremont cottonwood and other cottonwoods (Populus spp.) are naturally maintained by periodic winter and spring floods [31,58,115]. Dams and reservoir systems that change the natural timing and volume of water flow reduce the recruitment and vigor of Fremont cottonwood stands . In the absence of periodic flooding, succession proceeds, and the cottonwoods are eventually replaced by more shade-tolerant species (for example, western honey mesquite) . Flooding and time between floods are the driving successional forces in these communities .
Lowe  has called Fremont cottonwood associations a "distinctive climax biotic community." According to Johnson  Fremont cottonwood is both a "climax" and "pioneer" in Clementsian successional terminology. In Arizona, Asplund and Gooch  found that germination and establishment of Fremont cottonwood could take place in the absence of other species. Replacement of species does not occur; therefore, biological succession is not a good descriptor of the interspecific dynamics of these riparian communities . Fremont cottonwood is "considered an important member of the climax riparian vegetation in the Sacramento Valley" of California. In Utah, Fremont cottonwood occurs in mid-seral successional stages, not climax .
Fremont cottonwood is a fast-growing [88,92] obligate seeder , and reproduction primarily comes from establishment of wind-borne seeds [31,68,69,88]. Asexual regeneration occurs following crown and branch damage, uprooting, or flood-related disturbance . Regeneration is tied to the annual runoff regime of the area . Mortality of both saplings and mature trees can be great following major flooding events, but recruitment takes place on the newly created microsites .
Sexual reproduction: Fremont cottonwood reaches reproductive maturity between 5 and 10 years of age . Flowers are produced early in the spring and are entirely wind pollinated [50,58]. Large crops of seed are produced in the spring; the seeds have a cottony tuft of trichomes that enables them to float long distances in the wind  and on water. Seeds may not be fully viable when dispersed . Seeds typically germinate within 24 to 48 hours on suitable seedbeds, but seeds may remain viable for 1 to 5 weeks after dispersal [26,57,58]. Viability is lost if a suitable microsite is not found within 2 or 3 days of seed becoming wet .
Suitable recruitment sites are created by the floodwaters of spring run-off. Seeds germinate almost exclusively on the freshly deposited, exposed alluvium left by receding floodwaters. The availability of this type of moist, exposed habitat during and 6 to 8 weeks after seed dispersal is crucial because of the limited period of seed viability . Abandoned secondary and tertiary stream channels are valuable recruitment sites because subsurface water is available and some protection from scouring is provided .
Vegetative regeneration: Cottonwood species (Populus spp.) reproduce vegetatively by sprouting from stumps and root crowns, by forming suckers (adventitious shoots on roots) [2,26,49,50,79], and from stem cuttings . Root suckering has been observed to be the predominant method of regeneration of Fremont cottonwood in some areas in Utah . Root or bole sprouting often occurs after some injury (uprooting, broken branches) . Sprouting from lateral buds on stems occurs when there is contact with moist alluvial soil .
Growth: Root growth of young Fremont cottonwood seedlings is very rapid on favorable sites. Average growth rate is 0.16 to 0.47 inch (4-12 mm) [26,143], and a growth rate of 0.5 inch (13.5 mm) per day has been observed over a 4-day period . Because the upper layers of the moist alluvium dry rapidly with the onset of warmer summer temperatures, rapid root growth is essential in order to reach depths where a supply of water is available. Fremont cottonwood is vulnerable to droughts before the roots reach seasonal alluvial water tables . Rooting depths in mature stands are 9.8 to 16.4 feet (3-5 m) [26,166].
Growth Form (according to Raunkiær Life-form classification)
More info for the term: phanerophyte
RAUNKIAER LIFE FORM :
Life History and Behavior
In general, Fremont cottonwood 1st flowers early in the spring, before leaf emergence, and finishes by the end of May. Seed drop roughly coincides with the receding of spring floodwaters. Cottonwoods are dormant during the fall. Leaf senescence occurs in late September and abscission in mid-October. General dates for some phenological stages of Fremont cottonwood are as follows [8,26,27,31,58]:
|Location||Begins flowering||Full flower||Ends flowering||Seeds ripen & disperse|
|central AZ||----||Feb 15-March 15||----||March-April|
National NatureServe Conservation Status
Rounded National Status Rank: NNR - Unranked
NatureServe Conservation Status
Rounded Global Status Rank: G5 - Secure
In Texas, the Fremont cottonwood-Goodding willow (Salix gooddingii) Series is listed as "very rare and local throughout range or found locally in restricted range, 21 to 100 occurrences (threatened throughout range)" and "rare or uncommon, 21 to 100 occurrences" .
Please consult the PLANTS Web site and your State Department of Natural Resources for this plant’s current status, such as, state noxious status and wetland indicator values.
Fremont cottonwood communities are declining as a result of human
activities. A 1914 survey along the Gila River of Arizona showed 1,584
acres (641 ha) - 33% of the survey area - was occupied by Fremont and
other cottonwoods. Fremont cottonwood was the most widespread riparian community
of the Southwest. A 1944 survey of the same area showed on 160 acres (65 ha) so
occupied; by 1964, Fremont cottonwood was no longer a cover type: only a few
scattered trees remained .
Cattle grazing prevents successful regeneration of Fremont
cottonwood seedlings , and exclusion of grazing in Fremont cottonwood
riparian zones has been recommended [68,134,137,159].
However, Asplund and Gooch  maintain that the impacts of grazing are unclear
that recruitment is affected more by flooding and the creation of suitable
habitat than by grazing pressure.
Fremont cottonwoods and other components of riparian streamside stands are important in
erosion control and fisheries production; they stabilize banks and provide for
thermal cover and debris recruitment [77,126]. If possible, buffer strips of
these woodlands should
be maintained upland from streams, rivers, lakes, and ponds .
Regulating stream flows to mimic the natural flood regime (duration, peak flow,
and timing) could be used to establish
Fremont cottonwood and decrease saltcedar . Decreased flooding, stabilized flows, introduction of exotics
Russian-olive, and leafy spurge (Euphorbia esula)), water diversion due to
damming and agricultural use, and stream channelization have led to drought
stress and the subsequent decrease in Fremont cottonwood and associated riparian
species [26,36]. The loss of Fremont cottonwoods could mean the
loss of the riparian woodland ecosystem . See black cottonwood for further information on the effects of watercourse damming and
stream diversion on Fremont and other cottonwoods.
Cultivars, improved and selected materials (and area of origin)
Containerized Fremont's cottonwood samplings are available from most nurseries in the areas where adapted. We recommend using plants from the same region, elevation, climate, soil type, moisture or hydrologic regime as you are replanting.
Contact your local Natural Resources Conservation Service (formerly Soil Conservation Service) office for more information. Look in the phone book under ”United States Government.” The Natural Resources Conservation Service will be listed under the subheading “Department of Agriculture.”
Howe and Knopf (1991) conclude that to ensure the survival of cottonwood riparian communities along the Rio Grande, resource managers need to implement strategies to enhance cottonwood regeneration and survival, and control the spread of exotic species.
Decadent age structures in cottonwood forest consist of stands composed of large old trees but few saplings or small trees. Several studies have implicated unregulated livestock grazing as an important cause of decadent age structures in cottonwood forests (Brotherson et al. 1983; Fenner et al. 1984; Rucks 1984; Shanfield 1984). Glinski (1977) showed a negative correlation between grazing levels and Fremont's cottonwood recruitment. Several studies showed fewer cottonwood seedlings in grazed than in non-grazed areas (Crouch 1979; Reichenbacher 1984).
Livestock grazing has widely been identified as a leading factor causing or contributing to degradation of riparian habitats in the western United States (U.S. General Accounting Office 1988; Chaney et al. 1990, Fleischner 1994, Ohmart 1996). Livestock grazing can alter vegetative structure and composition of riparian habitat. Overgrazing, especially by livestock and big game, frequently changes plant species composition and growth form, density of stands, vigor, seed production of plants, and insect production. Bull and Slovlin (1982) attributed to livestock grazing the paucity of deciduous woody vegetation that was required by some bird species along Oregon streams.
Schulz and Leininger (1991) found that bird species are differentially affected by cattle grazing in riparian areas. Livestock grazing causes the replacement of bird and mammal species requiring the vertical vegetation structure of riparian habitat to species, which are ubiquitous in their habitat preferences. Previous heavy cattle grazing changed the bird and small mammal community composition through reduction of shrub and herbaceous cover.
Riparian zones can be managed for non-game species richness by maintaining high structural diversity of vegetation. Species that are sensitive to grazing pressure should be monitored as indicators of habitat change. Johnson (1985) pointed out the need to coordinate range and wildlife habitat management to ensure the existence of sensitive wildlife species that are negatively impacted by livestock grazing. Woody plant species increase rapidly when riparian areas are protected from livestock grazing. The woody structural component of the vegetation is essential for wildlife species that are obligate inhabitants of riparian habitat, and in providing hiding cover and stabilizing streambanks for fish habitat.
Slovlin (1984) recommended a 5-year rest from cattle grazing to re-establish healthy stands of riparian vegetation such as cottonwood and willows. Siekert et al. (1985) reported that spring grazing showed no significant changes in channel morphology, whereas summer and fall grazing did. However, even with limited seasonal grazing, all tree seedling would be eliminated. Marlow and Pogacnik (1985) recommended fencing riparian habitat, rest-rotation, light grazing (<20% forage removal), and grazing after streambanks have dried to 10% moisture.
Relevance to Humans and Ecosystems
Other uses and values
Native Americans ate the inner bark of Fremont cottonwood for antiscorbutic [18,100]. The bark and leaves were used to make poultices to relieve swelling, treat cuts, cure headaches, and wash broken limbs, and to treat saddle sores and swollen legs of horses [18,166]. The twigs were used by the Pima for basket materials , and Cahuilla tribes used the wood for mortars and tools . In northern Mexico, small industries utilize the wood to make bowls and small statues . Fremont cottonwoods were used by the Pueblo tribes for drums and were the preferred wood species for Quechan cremations 
Value for rehabilitation of disturbed sites
Fremont cottonwood's rapid early growth makes it well suited for revegetating riparian sites [47,126]. It has been successfully planted in many riparian rehabilitation projects [36,82,92,126,164] and is recommended for revegetating areas in the Southwest where invasive saltcedar has been removed [88,99]. Fremont cottonwood, along with willows and other native plants, has also been used to restore, enhance, or create bird habitat in riparian areas [46,63].
Fremont cottonwood can be successfully planted in chaparral-mountain shrub, big sagebrush, pinyon-juniper, and desert shrub communities where there is sufficient moisture [126,127]. It can grow on disturbed sites removed from groundwater as long as good moisture is available in the spring, but on such sites it will exhibit a shrubby growth form . Plants readily establish from nursery-grown containerized stock and rooted cuttings . Growth of seedlings is rapid on favorable sites, and the roots of established seedlings are effective stabilizers of alluvial soil [47,82,126].
The value of Fremont cottonwood as cover for domestic animals and wildlife has been rated as follows :
|Small non-game birds||good|
|Upland game birds||fair|
Importance to Livestock and Wildlife
Riparian habitats occupied by Fremont cottonwood add diversity to the arid and semiarid environments of the American Southwest [91,127]. Fremont cottonwood and Fremont cottonwood-willow stands provide valuable habitat for many species of birds and other wildlife in Arizona, California, Colorado, Nevada, New Mexico, and Texas. Species such as golden eagle, Swainson's hawk, red-tailed hawk, and Bell's vireo build their nests in the crown [17,72,131,137], while various cavity-nesting birds nest in the dead trunks and limbs of Fremont cottonwood [60,65,79]. In Nevada, Fremont cottonwood sites are breeding areas for great blue heron . Birds known to have a high affinity for Fremont cottonwood stands include hawks (gray, black, zone-tailed, red-tailed) [61,89,131], bald eagle , and woodpeckers (downy and ladder-backed) . Fremont cottonwood communities also provide cover, nesting, and foraging habitats for other birds [11,52,53,60,89,90,102,109,130], ringtail , squirrels, beavers , and other rodents [3,109].
In California, Fremont cottonwood-willow and willow communities provide the greatest overstory canopy coverage of any desert riparian vegetation type. Consequently, they provide a wider range of perches, nest sites, and foraging substrates; they are known to support roughly 2 to 5 times more breeding bird species than vegetation types with less overstory . More than 50% of the bird species breeding in the homogeneous Fremont cottonwood stands along the Verde River in Arizona depended exclusively on this vegetation type .
Fremont cottonwood communities provide shade for domestic livestock, provide a food source for beavers, elk, deer, and squirrels, and help maintain mesic habitats for upland amphibian and reptile species in the Sonoran Desert [28,94,103].
Wood Products Value
Fremont cottonwood is moderately light in weight and color, uniform in texture, and has a fairly straight grain. The wood is relatively soft and weak, but its strength-to-weight ratio is high [13,45]. The untreated wood of all cottonwoods (Populus spp.) has low resistance to decay when in contact with the ground .
Primary wood products include lumber, veneer, and pulpwood [13,92,103]. Finished products include crates and boxes for food storage and pallets [13,88]. The wood is used locally in the southwestern United States for fenceposts and firewood [13,18,88,92,103] and is preferred for kilning bricks in Arizona .
Fremont cottonwood is rated as fair for both energy and protein content. The nutritional value of Fremont cottonwood for wildlife has been rated as
|Small non-game bird||fair|
|Upland game bird||poor|
|Domestic sheep||poor to fair||fair|
|Mule deer||poor to fair||----|
|White-tailed deer||poor to fair||----|
This species has been called "sweet
cottonwood" because horses eat the inner bark .
Ethnobotanic: The sweet and starchy sap can be consumed raw or cooked. The bark is bitter, but edible. It can be scraped off and eaten, cooked in strips like soup noodles, or dried and powdered as a flour substitute. The inner bark of cottonwoods and aspens were used for man and horse in hard times. Some Indians preferred it because of its sweetness.
The active biochemical constituents are salicin and populin, the precursors of aspirin that are useful wherever a fever needs reducing or an anti-inflammatory is appropriate (Moore 1979). The bark is the most effective part for tea but is rather bitter; for this reason the leaves are often preferred. Leaf buds make an excellent ointment for burns and skin irritations. A wash of the bark is applied externally for cuts, bruises, abrasions, burns and fetid perspiration, as well as healing chafing sores on horses. A poultice can be used for sprains, muscle pain, and swollen joints. A salve can be made that cleanses and conditions the skin when used regularly. Taken internally, it is an anti-inflammatory agent, reduces fever, indigestion, aids coughs from colds, expels worms and intestinal parasites, is effective against scurvy, heart troubles, back pain, excessive menses, urinary tract infections, is a diuretic, and is used to prevent premature birth.
The Hopi Indians of Arizona consider the cottonwood tree sacred and carve Kachina dolls from the roots of the tree. They believe the rustle of the wind through the quaking leaves to be the gods speaking to people (Strike 1994).
Several California tribes used Populus roots to make loosely twined baskets. The Hupa, from Northern California, use cottonwood roots to begin making twined baskets. The Maidu and Yokuts Indians use cottonwood twigs in their basketry (Strike 1994).
Chumash skirts were made of fibers of Populus inner bark. Cordage, made from the inner bark of cottonwood or milkweed, held the rest of the fibers hanging freely. Sometimes small teardrop-shaped pieces of asphaltum, shell beads or Pinus seeds were used as weights to make the fibers hang properly. Wintun also used Populus fibers for skirts and for padding baby cradles.
Other Uses: Ecological diversity, bank and sediment stabilization, maintenance of channel morphology, water quality improvement, ground-water recharge, flood abatement, fish and wildlife habitat.
Riparian Ecosystem Services and Functions: The riparian zone essentially encompasses those alluvial sediment deposits where river and alluvial ground water supplement that available from local precipitation. High-to-low elevations, north-south and east-west gradients, and steep-to-shallow terrain all influence the relationship between geomorphic and fluvial processes and vegetation community structure. Riparian ecosystem functions include the following:
• Ecological diversity.
• Riparian vegetation stabilizes sediment, thus preventing excessive soil erosion.
• Water quality is improved through filtration and trapping of sediment, nutrients and pollutants.
• Riparian vegetation tends to prevent the river from down-cutting or cutting a straight path (channeling), thus promoting a sinuous course, ground-water recharge, and maintenance of an elevated water table.
• Structurally complex riparian vegetation communities provide many different habitats and support a diverse array of animal species. Different groups of animals occupy or use the different layers of vegetation, and this multi-story arrangement is often present nowhere else in the arid landscapes.
• Canopies of plants growing on streambanks provide shade, cooling stream water, while roots stabilize and create overhanging banks, providing habitat for fish and other aquatic organisms
Riparian habitat provides living conditions for a greater variety of wildlife than any other habitat type found in California. Use of riparian areas by wildlife species is affected by diversity and volume of foliage, presence of water, availability of "edge" habitat, and high levels of insect populations. Valley-foothill riparian habitats provide food, water migration and dispersal corridors, and escape, nesting and thermal cover for an abundance of wildlife. About 25 percent of the 502 California native land mammal species and subspecies are largely dependent on riparian ecosystems. Additionally, 55 species of mammals are known to use California's Central Valley riparian communities (Trapp et al. 1985). At least 21 mammal species or subspecies have been identified as being particularly vulnerable to loss of riparian habitat (Williams and Kilburn 1984). At least 50 amphibians and reptiles occur in lowland riparian systems (Brode and Bury 1985).
Wildlife: California's riparian forests support a high diversity of breeding birds (Miller 1951). In one study conducted on the Sacramento River, 147 bird species were recorded as nesters or winter visitants (Laymon 1985). The percentage of breeding individuals, which are migratory, is very high in the cottonwood-willow habitat. Humid conditions in the cottonwood-willow forest may promote more lush plant growth, higher invertebrate populations and; therefore, more available food for flycatchers, warblers and other migratory, insectivorous birds. Riparian areas support up to 10.6 times the density of migrant birds per hectare as adjacent non-riparian areas (Stevens et al. 1977). Most of these migratory birds belong to the foliage insect (47%) or air insect (34%) foraging guilds.
Grouse, quail, and other birds eat cottonwood buds and catkins (Martin et al. 1951). Bark, twigs, and leaves are eaten by ungulates and rabbits, while beavers and porcupines relish the bark and wood.
Since European settlement, the nesting riparian forest avifauna has changed significantly. Double-crested cormorants, great blue heron, great egret, Cooper's hawk, bald eagle, yellow-billed cuckoo, willow flycatcher, bell's vireo, warbling vireo, yellow warbler, and common yellow throat have been severely negatively impacted. Parasitism by brown-headed cowbirds has significantly negatively impacted willow flycatcher, Bell's vireo, warbling vireo, yellow warbler and common yellow throat. They burden other species with the task of incubating their eggs and raising their young.
Fremont's cottonwood is one of several species which constitutes the majority of the diet of beavers (Castor canadensis) (Stromberg 1993). Beavers, once a dominant aquatic mammal in riparian systems, have been significantly reduced in many riparian areas through trapping, shooting, in-stream flow reductions, and other factors.
Recreation: Recreational use of the riparian zone is many times that of other habitats. People are drawn to the cool, shady environment along flowing streams for camping, picnicking, hiking, birding, photography, hunting, and fishing. These areas contain water, interesting plants and animals, shade, and numerous other enjoyable features in the otherwise arid and semiarid environments.
The impact of recreational use on wildlife varies with the season and with the type, intensity and duration of use. Construction of trails, picnic tables, and docks encourages recreational use and increases conflict with wildlife. Recreational use may also reduce water quality because of proliferation of human wastes.
Livestock: Riparian ecosystems offer water, shade, and food for domestic livestock. Cattle and sheep congregate in riparian areas, particularly during hot or dry periods. Overgrazing of domestic livestock in riparian areas destroys riparian ground cover, disrupts the reproductive cycle of cottonwood trees, destabilizes streambanks, and thus increases sediment loads to streams. At periods in the year when the soil is not too wet, the leafage, twigs and shoots of Fremont cottonwood are browsed by all domestic grazing animals and deer. The twigs are cropped especially close by sheep, goats, and deer. The browse rating for cottonwood is good to fair for goats; fair to poor for sheep and deer; poor for cattle; and useless for horses (Sampson et al. 1981).
Restoration Concerns: Many land uses in arid watersheds significantly decrease or destroy cottonwood riparian forests. Timber harvest often adversely affects flood flows, which often become larger and flashier and carry increased sediment. Buffer strips can help reduce sedimentation rates and flood velocities.
Stream diversion for irrigation may reduce surface flows to a level insufficient to maintain cottonwood vegetation. Ground water pumping lowers local and regional water tables and reduces stream flow, which can eliminate or weaken riparian vegetation.
Runoff from hardened urban watersheds is immediate and intense, and sometimes actually lowers nearby riparian water tables as it causes rapid erosion and down-cutting in stream channels.
Two introduced weedy riparian species that continue to be recommended and distributed by commercial plant nurseries are Russian olive (Eleagnus angustifolia) and tamarisk or salt cedar (Tamarix chinensis). Intensive or poorly timed livestock grazing and dam-induced changes in flood timing and magnitude often favor the survival of these introduced species and allow them to displace native species. These species are very difficult to remove from human-impacted landscapes and are more competitive than cottonwood.
Populus fremontii, the Fremont's cottonwood or Alamo cottonwood, is a cottonwood (and thus a poplar) native to riparian zones of the Southwestern United States and northern through central Mexico. It is one of three species in Populus sect. Aigeiros
The tree is native to southwestern North America: in the Southwestern U.S. from California: eastwards through Nevada, Utah and Arizona and New Mexico, to Texas and Colorado; and in Mexico in the states of Baja California, Baja California Sur, Sonora , Chihuahua, Coahuila, Nuevo Leon, Mexico State, and Puebla.
Populus fremontii is a large tree growing from 12 m (39 ft) - 35 m (115 ft) in height with a wide crown, with a trunk up to 1.5 m (4.9 ft) in diameter. The bark is smooth when young, becoming deeply fissured with whitish cracked bark on old trees.
The 3 cm (1.2 in) - 7 cm (2.8 in) long leaves, are cordate (heart-shaped) with an elongate tip, with white veins and coarse crenate teeth along the sides, glabrous to hairy, and often stained with milky resin. Autumn colors occur from October–November, mainly a bright yellow, also orange, rarely red.
The Inflorescence consists of a long drooping catkin, which blooms from March to April. The fruit is a wind dispersed achene, that appears to look like patches of cotton hanging from limbs, thus the name cottonwood.
The largest known Populus fremontii tree in the United States grows in Skull Valley, Arizona. In 2012 it had a measured circumference of 557 inches (14.1 m) or 46.4 feet, height of 102 feet (31 m), and a spread of 149.5 feet (45.6 m).
Subspecies or varieties
Two subspecies are currently recognized. Some confusion due to hybridization with a Rio Grande subspecies of Populus deltoides subsp. wislizeni had originally placed this Eastern Cottonwood subspecies as a P. fremontii subspecies, but it was removed in 1977.
- Populus fremontii subsp. fremontii, with synonyms P. f. var. arizonica - Sarg. and P. f. var. macdougalii - (Rose) Jeps. from California and west of the Continental Divide
- Populus fremontii subsp. metesae - Eckenwal., of arid areas of Mexico, and widely planted elsewhere, generally east of the Continental Divide
Populus fremontii is cultivated as an ornamental tree and Riparian zone restoration tree. It is used in planting for: wildlife food and shelter habitats and ecological restoration; larger native plant and wildlife gardens and natural landscaping projects, windbreaks, erosion control, and shade for recreation facilities, parks, and livestock.
Fremont cottonwood was used in the past by settlers and ranchers for fuel and fence posts.
- Traditional medicine
Native Americans in the Western United States and Mexico used parts of the Fremont cottonwood variously for a medicine, in basket weaving, tool making, and for musical instruments. The inner bark of Fremont cottonwood contains vitamin C and was chewed as an antiscorbutic, or treatment for vitamin C deficiency. The barks and leaves could be used to make poultices to reduce inflammation or to treat wounds.
The Pima people of southern Arizona and northern Mexico lived along Sonoran Desert watercourses and used twigs from the tree in the fine and intricate baskets they wove. The Cahuilla people of southern California used the tree's wood for tool making, the Pueblo peoples for drums, and the Lower Colorado River Quechan people in ritual cremations.
- Populus fremontii information from NPGS/GRIN
- USDA Plants Profile for Populus fremontii (Fremont's cottonwood)
- "Jepson Manual treatment: Populus fremontii subsp. fremontii". University of California Press, ©Copyright 1993 by the Regents of the University of California.
- "USDA Plant Fact Sheet". United States Department of Agriculture. Retrieved February 5, 2002.
- "Range Plants of Utah". Utah State University. Retrieved 2002.
- "Populus fremontii ssp. fremontii". American Forests.
- Eckenwalder, J.E. (1977). "North American cottonwoods (Populus, Salicaceae) of sections Abaso and Aigeiros". Journal of the Arnold Arboretum 58 (3): 193–208.
- "Digital Desert: Mojave Desert". MojaveDesert.net. n.d.
Names and Taxonomy
Recognized infrataxa are as follows:
fremontii ssp. fremontii Wats. Fremont cottonwood [49,82,96]
fremontii ssp. mesetae Eckenwalder meseta cottonwood [82,95,96]
Fremont cottonwood hybridizes with narrowleaf cottonwood (P.
angustifolia) to produce P. × hinkleyana Correll
[45,94,108] and with black cottonwood (P. trichocarpa) to produce P. ×
parryi Sarg. [45,108]. In California, where the ranges of black and Fremont cottonwood
overlap, the 2 species are reported to occur together without hybridization .
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