Regularity: Regularly occurring
Deer brush is a native, drought-deciduous shrub reaching 3 to 18 feet (1-6 m) in height at maturity. It is loosely branched and spreading in form. Flowers are borne in compound clusters. The fruit is a sticky capsule containing small, obovoid seeds [31,59]. Nitrogen-fixing actinomycetes form nodules in deer brush roots [17,25].
Deer brush stems, excluding the root crown, live about 35 years. The stem of one specimen has been aged at 47 years. Maximum age attained by roots and root crowns has not been determined, but life span of these organs can be more than 35 years if periodic top-kill occurs .
Catalog Number: US 613402
Collection: Smithsonian Institution, National Museum of Natural History, Department of Botany
Preparation: Pressed specimen
Collector(s): L. Abrams & E. A. McGregor
Year Collected: 1908
Locality: San Bernardino Mountains, Clighorn Canyon., San Bernardino, California, United States, North America
Elevation (m): 1372 to 1372
- Isolectotype: Greene, E. L. 1908. Bull. New York Bot. Gard. 6: 409.
Deer brush grows on well-drained soils of all textures . Slope varies from gentle to steep . In California, deer brush occurs primarily on the west slope of the Cascade-Sierra Nevada crest [22,33]. In Oregon, deer brush occurs on both sides of the Cascade Range .
Elevational ranges of deer brush are as follows:Arizona 3,500 to 7,000 feet (1,100-2,100 m) 
northern California 2,000 to 4,000 feet (600-1,200 m) [22,64]
central Sierra Nevada 3,000 to 5,550 feet (900-1,700 m)
southern California 5,000 to 7,000 feet (1,500-2,100 m) 
Oregon 2,000 to 4,000 feet (600-1,200 m)
Washington 2,000 to 4,000 feet (600-1,200 m) 
More info for the terms: natural, shrubs, tree, wildfire
Deer brush grows in open sun to partial shade. When overtopped by trees, deer brush dies out [22,30,74]. It is typically successional after fire, landslide, logging, mining, or other stand-replacing events [7,22,33]. Deer brush seedlings establish in the initial postdisturbance community. If fire or other disturbance is frequent enough to prevent conifers from establishing a canopy, deer brush and other shrubs may occupy a site indefinitely . A shrubfield containing deer brush, on the Tahoe National Forest, has a history of wildfire occurrence at approximate 10-year intervals. The shrubfield has remained stable for over 100 years . More often, deer brush is replaced by conifers [7,22]. In montane chaparral, herbs, deer brush, and other shrubs are replaced by pines (Pinus spp.). In the absence of fire, pines are replaced by firs (Abies spp.) and other shade-tolerant tree species [30,76]. On the Klamath National Forest of California, Stuart and others  identified two seral communities in which deer brush was an important component of the vegetation after stand-replacing events in old-growth Douglas-fir (Pseudotsuga menziesii). After wildfire and no subsequent salvage operation, a deer brush-canyon live oak-blue wildrye (Quercus chrysolepis-Elymus glaucus) community developed. After wildfire followed by salvage, or logging followed by site preparation and planting of Douglas-fir seedlings, a tanoak-Pacific madrone-(Lithocarpus densiflorus-Arbutus menziesii)-deer brush community developed. The authors speculated that with either successional pathway, natural release of Douglas-fir would not occur for at least 50 years, but the long-term fertility of the deer brush-canyon live oak-blue wildrye community may be greater because nitrogen-fixing deer brush is the primary dominant.
Seed reproduction: Deer brush first produces seed at about 4 years of age . Ripe seed is forcibly ejected from the capsule when the capsule dries and splits . Deer brush is a seed banking species. Seed is stored in extremely high densities in duff and the upper few centimeters of mineral soil. Anderson  estimated that the deer brush seed population in a mixed coniferous forest in northern California was greater than 2 million seeds per hectare. Viability of the seed averaged 90.6 percent in the laboratory . Similarly, Kauffman and Martin [37,38] reported a range of 60 to 90 percent viability of deer brush seed from three northern California mixed-conifer forests. Viability of deer brush seed is generally high, and the seed is long-lived. Quick and Quick  reported 90 percent viability of 24-year-old seed. Other researchers have suggested that deer brush seed remains viable for well over 100 years [4,22,62].
Seed is dormant until the hard seedcoat is scarified by fire or mechanical disturbance such as logging [19,22]. Optimal temperatures for scarification range from 170 to 195 degrees Fahrenheit (77-90 deg C) . High-consumptive fire (> 90% of duff burned) kills most seed in duff, but most seed in mineral soil survives. Anderson  found that following one high-consumptive fire, 12.5 percent of seed in duff and 52.4 percent of seed in mineral soil was viable. Seed requires stratification follow scarification, and usually germinates in spring . Keeley  reported that light inhibited germination, an unusual response, and that charate (charred wood powder) had no effect on germination.
Best establishment occurs with seed in bare mineral soil [7,22]. In a greenhouse study, seeds planted at one-half inch (1 cm) when in shade and at 1 inch (2.5 cm) when in sun showed better seedling emergence than seeds planted at greater or lesser depths. Emergence did not occur with seeds planted on the soil surface . Nearly all seedling establishment occurs in the first postfire spring; establishment after the second postfire year is rare . Plants typically average 3 to 4 inches (8-18 cm) in height at the end of their first growing season and 8 inches (20 cm) in height at the end of the second growing season [21,22,77].
Vegetative reproduction: Sprouts grow more rapidly than seedlings, reaching a height of 30 or more inches (76 cm) in their first year . Age at which deer brush sprouts first produce seed is undocumented; however, sprouts of most Ceanothus species produce seed after 3 to 6 years . When deer brush plants are top-killed before they become decadent, roots remain alive, and root crowns retain the ability to sprout for years beyond the 35-year life expectancy of other stem tissue. Without periodic top-kill, root systems and root crowns of decadent plants die .
Life History and Behavior
Deer brush flowers from spring to early fall [31,40,59]. Heaviest flowering occurs in May and June , with seeds dispersing in summer . Since deer brush is drought-deciduous, most leaves are shed in summer. A few leaves are usually retained throughout winter [21,31].
Molecular Biology and Genetics
Barcode data: Ceanothus integerrimus
Statistics of barcoding coverage: Ceanothus integerrimus
Public Records: 1
Specimens with Barcodes: 1
Species With Barcodes: 1
National NatureServe Conservation Status
Rounded National Status Rank: N5 - Secure
NatureServe Conservation Status
Rounded Global Status Rank: G5 - Secure
Relevance to Humans and Ecosystems
Value for rehabilitation of disturbed sites
Deer brush is recommended for use on restoration projects due to its nitrogen-fixing ability . Transplanting wild 1-, 2-, and 3-year-old shrubs has been successful in the Sierra Nevada . Growing stock from seed has shown good results, although seed requires several months of pregermination treatment. Reed  has compiled procedures for germinating seed in the laboratory.
Importance to Livestock and Wildlife
Deer brush provides high-quality, palatable, and often abundant forage for livestock and wildlife, especially deer [1,22,66]. On Arizona chaparral of the Tonto National Forest, deer brush was one of three principle browse species used by white-tailed deer in fall . In California, deer brush is the most important summer browse species for mule deer and livestock in the ponderosa pine belt. Mule deer also make moderate to heavy use of it on California's winter ranges [22,49].
Porcupine browse deer brush stems. Gambel quail have been observed eating large quantities of the seed .
Deer brush leaves are high in protein, and calcium levels are high in both leaves and twigs. However, based on the nutritional standard for lactating cows, deer brush provides inadequate levels of phosphorus and digestible energy. Overall, browse quality decreases from late spring to late summer. On the Sierra National Forest, nutritional quality of deer brush browse varied significantly by year, but not by shrub age or degree of overstory canopy closure. Average nutritional content of deer brush, collected every 2 weeks from June 1 to September 8, 1982 and 1983, follows. Data are means (standard errors) .
|Neutral-detergent fiber (%)||1982||33.66 (1.92)||65.48*(2.25)|
|Acid-detergent fiber (%)||1982||19.85*(1.71)||48.42*(2.02)|
|In-vitro digestible dry matter||1982||53.93*(3.64)||33.49 (1.70)|
|Digestible energy (kcal/g)||1982||2.42*(0.18)||1.48 (0.08)|
|Crude protein (%)||1982||18.15*(0.43)||8.22*(0.34)|
|Phosphorus (%)||1982||0.18 (0.01)||0.16*(0.01)|
|*Significant (P<0.05) difference with respect to year of collection.|
Average protein content of deer brush collected from various California locations varied seasonally as follows :
|25.2 %||13.7 %||8.9 %|
Cover value: No information was available on this topic as of 1997.
Ceanothus integerrimus (deer brush) is a woody shrub in the family Rhamnaceae, native to the western United States, in Arizona, New Mexico, California, Oregon, and Washington. It grows in montane chaparral and woodlands regions, in hardwood forests, and in fir, spruce, and Ponderosa pine plant communities, being most abundant in the California chaparral and woodlands and Sierra Nevada.
Ceanothus integerrimus is a deciduous shrub from 1–4 metres (3.3–13.1 ft) tall with an open ascending to erect branch habit. It is a drought-tolerant phanerophyte. Nitrogen-fixing actinomycete bacteria form root nodules on Ceanothus roots. Its stems are round yellow to pale green in color with either small soft to straight stiff sharp hairs parallel to or in contact with the surface of the stem,.
The leaves are glossy, deciduous and 2.5–8 cm long. Leaves grow alternately on stems. The leaf petioles are less than 15 mm in length and the stipules are also deciduous. The leaf blade is lanceolate, elliptical or oblong to widely ovate in shape. Leaves can have one to two ribs from the base; they are also generally thin and have an acute to obtuse tip. Leaf margins are either entire or slightly dentate, more so towards the leaf tip. Leaf surfaces are light green and are ciliate or contain hairs visible only by magnification. The lower leaves are also hairy and lighter in color.
The flowers are white or blue and rarely pink in color. They are produced in raceme clusters of 15 centimeters or less and contain both male and female organs. The fruit is a sticky valved capsule about 4–5 mm in diameter with a slight crest; the seed is ejected from the capsule after splitting.
It regenerates by seed, shoot formation from the crown and stem, and also by layering when branches come in contact with soil. It has been suggested that some Ceanothus species do not resprout from the root after the crown has burned as a result of fire where most other species are able to regenerate. Pollination of flowers is primarily by bees.
Seed production occurs after about four years of age. High densities of seeds occur in the upper soil of Ceanothus communities. Seeds remain viable up to 24 years or more. Seed dormancy is broken by the removal of the seed coat by fire scarification or physical disturbance. Seeds germinate best at about 1 inch soil depth in shady areas in the spring following fire scarification.
- Ceanothus integerrimus var. californicus. Leaves elliptic, lanceolate or oblong to ovate in shape and are three ribbed, from the leaf base. Leaf surfaces have small hairs and the undersides are less hairy than the surface. Flowers generally white or blue.
- Ceanothus integerrimus var. integerrimus.
- Ceanothus integerrimus var. macrothyrsus. Leaf blades oblong or ovate. Leaf bases are three ribbed at the base. Leaf surfaces are pubescent on both the surface and undersides. Flowers are white.
- Ceanothus integerrimus var. puberulus. Leaf blades elliptical or lanceolate and oblong to obovate in shape. Leaf base is three ribbed from the leaf base. Leaves are also pubescent on both sides. Flowers white.
C. integerrimus is an important part of forest regeneration after wildfires by providing nitrogen. It does this by creating nitrogen rich patches in the soil. The nitrogen source is created by its root association with nitrogen fixing bacteria.
Deer and specifically mule deer feed on C. integerrimus. Porcupines and quail have also been observed eating the stems and seeds. Nutritionally leaves are a good source of protein and stems and leaves also contain high levels of calcium. However, nutritional quality of leaves is seasonal and appears to be best from fall to early spring.
Indigenous peoples of California use the branches to treat women after childbirth. The Miwok Indians of Northern California also use the branches of this plant in weaving complex baskets. The Concow tribe call the tree hē′-bē (Konkow language).
- "The Plant List: A Working List of All Plant Species". Retrieved 14 December 2014.
- (Kellogg) Benson
- (Torrey) Benson
- (Greene) Abrams
- Chesnut, Victor King (1902). Plants used by the Indians of Mendocino County, California. Government Printing Office. p. 404. Retrieved 24 August 2012.
- Debano, L. F. & Conrad, C. E. (1978). The Effect of Fire on Nutrients in the Chaparral Ecosystem. Ecology 59 (3): 489-497.
- Gibbens, R. R. P. & Schultz, A. M. (1963). Brush manipulation on a deer winter range. California Fish and Game 49 (2): 95-118. .
- Griffin, James R. (1982). Pine seedlings, native ground cover, and Lolium multiflorum on Marble-Cone burn, Santa Lucia Range, CA. Madrono 29 (3): 177-188.
- Jepson Flora Treatment: Ceanothus integerrimus
- Howard, Janet L. (1997). System Ceanothus integerrimus In: Fire Effects Information [Online]. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory. .
- Munz, P. A. & Keck, D. D. (1959). A California Flora with Supplement p. 973. University of California Press, Berkely, Los Angeles.
- Moerman, D. Native American Ethnobotany. Timber Press, Oregon: 1988.
- Oakley B. B., North, M. P., & Franklin, J. F. (2003). The effects of fire on soil nitrogen associated with patches of the actinorhizal shrub Ceanothus cordulatus. Plant and Soil 254: 35-46.
- Oswald, V. H. & Ahart, L. (1994). Manual of the Vascular Plants of Butte County, California p. 192. Native Plant Society, Sacramento.
- Raven, P. H. & Axelrod, D. I. (1977). Origin and relationships of the California Flora. University of California Publications in Botany 72. Sacramento: University of California Press.
- Russell, C. P. (1932). Seasonal Migration of Mule Deer. Ecological Monographs 2:1 pp. 1–46.
EOL content is automatically assembled from many different content providers. As a result, from time to time you may find pages on EOL that are confusing.
To request an improvement, please leave a comment on the page. Thank you!