H. Clay Smith
Cucumbertree (Magnolia acuminata), also called cucumber magnolia, yellow cucumbertree, yellow-flower magnolia, and mountain magnolia, is the most widespread and hardiest of the eight native magnolia species in the United States, and the only magnolia native to Canada. They reach their greatest size in moist soils of slopes and valleys in the mixed hardwood forests of the southern Appalachian Mountains. Growth is fairly rapid and maturity is reached in 80 to 120 years. The soft, durable, straight-grained wood is similar to yellow-poplar (Liriodendron tulipifera). They are often marketed together and used for pallets, crates, furniture, plywood, and special products. The seeds are eaten by birds and rodents and this tree is suitable for planting in parks.
Range and Habitat in Illinois
Regularity: Regularly occurring
Regularity: Regularly occurring
-The native range of cucumbertree.
Trees, deciduous, single-trunked, to 30 m. Bark dark gray, furrowed. Pith homogeneous. Twigs and foliar buds silvery-pubescent. Leaves distinctly alternate, not in terminal whorl-like clusters; stipules 3.2-4.3 × 1.4-1.6 cm, abaxially pilose. Leaf blade broadly ovate-elliptic, oblong to oblong-obovate, rarely somewhat rotund, (5-)10-25(-40) × 4-15(-26) cm, base cuneate to truncate or broadly rounded, often somewhat oblique, apex acuminate; surfaces abaxially pale green to whitish, pilose to nearly glabrous, adaxially green, glabrous or rarely scattered pilose. Flowers slightly aromatic, 6-9 cm across; spathaceous bracts 2, abaxially silky-pubescent; tepals erect, strongly glaucous to greenish or sometimes yellow to orange-yellow, outermost tepals reflexed, much shorter, green; stamens (50-)60-122(-139), 5-13 mm; filaments white; pistils (35-)40-45(-60). Follicetums oblong-cylindric, often asymmetric, 2-7 × 0.8-2.7 cm; follicles short-beaked, glabrous. Seeds heart-shaped, somewhat flattened to somewhat globose, 9-10 mm, smooth, aril reddish orange. 2n=76.
Magnolia virginiana Linnaeus var. (e) acuminata Linnaeus, Sp. Pl. 1: 536. 1753; Kobus acuminata (Linnaeus) Nieuwland; Magnolia acuminata var. alabamensis Ashe; M. acuminata var. aurea (Ashe) Ashe; M. acuminata subsp. cordata (Michaux) E. Murray; M. acuminata var. cordata (Michaux) Seringe; M. acuminata var. ludoviciana Sargent; M. acuminata var. ozarkensis Ashe; M. acuminata var. subcordata (Spach) Dandy; M. cordata Michaux; Tulipastrum acuminatum (Linnaeus) Small; T.acuminatum var. aureum Ashe; T.acuminatum var. flavum Small; T.acuminatum var. ludovicianum (Sargent) Ashe; T.acuminatum var. ozarkense (Ashe) Ashe; T.americanum Spach; T.americanum var.subcordatum Spach; T.cordatum (Michaux) Small
Habitat and Ecology
Magnolia acuminata is the hardiest and most widespread of the eight native Magnolia species in the USA. Unlike many species of Magnolia, this species does not have spectacular flowers but it does produce unusual small cucumber-like fruits in the autumn. This species prefers rich soils of bottom land and north to east slopes and is most plentiful in mountains and hills. The soils must be well drained, moist, and deep. Most slopes where this species is found are gentle to moderate, up to 25 percent, though the cucumber tree is also found on steeper slopes. The Cucumber tree is found in three orders and five suborders of soil. The dominant order, Inceptisols, occurs on approximately 60 percent of the species range, particularly in the Appalachians. On steep slopes greater than 25 percent, cucumber tree grows on coarse loams. On gentle to moderate slopes it is found on fine loams. Here, water is readily available to plants during more than one-half of the year or more than three consecutive months during the growing season. Soil textures are finer than loamy sand and these soils have a moderate to high nutrient content. Birds and other animals feed on the seeds and fruit of this species.
Despite the hardy nature of this magnolia, it is not commonly found in Britain where it was introduced by John Bartram in 1736. It prefers alkaline soils that are moist and well drained, and it cannot tolerate extreme winds or heat. In its natural habitat it can grow to 30 m (100 ft) in height but more often reaches around 20 m (75 ft).
The foliage of Magnolia acuminata means that it is well suited to providing shade and as a result is often planted in parks and gardens. As well as its long, pointed leaves and mini 'cucumbers', the tree can also be identified by its bark, which is a mix of orange, purple and dark brown usually in the form of narrow ridges.
Range and Habitat in Illinois
Soils and Topography
Cucumbertree is found in three orders and five suborders of soil (28). The dominant order, Inceptisols, occurs on approximately 60 percent of the species range, particularly in the Appalachians. On steep slopes greater than 25 percent, cucumbertree grows on coarse loams. On gentle to moderate slopes it is found on fine loams. Here, water is readily available to plants during more than one-half of the year or more than three consecutive months during the growing season. Soil textures are finer than loamy sand and these soils have a moderate to high nutrient content.
Approximately 35 percent of the soils are Ultisols, occurring on gentle to steep slopes in the southern range. These soils are low in nutrients. On slopes greater than 25 percent, cucumbertree grows on fine to coarse loams, clays, and on well-drained quartz sands. On slopes up to 25 percent it is confined to coarse loams (28).
The remaining soils on which cucumbertree grows are in the order Alfisols.
Associated Forest Cover
In the northern and central hardwoods and Appalachian Highlands, cucumbertree commonly is associated with sugar maple (Acer saccharum), yellowpoplar (Liriodendron tulipifera), yellow buckeye (Aesculus octandra), several oaks Quercus spp.), and black walnut (Juglans nigra). Common understory vegetation includes spring beauty (Claytonia caroliniana), trilliums (Trillium spp.), violets (Viola spp.), Solomons-seal (Polygonatum pubescens), and sweet cicely (Osmorhiza spp.). In the Allegheny Plateau of northern Pennsylvania and southern New York, cucumbertree usually is associated with black cherry (Prunus serotina), sugar maple, yellow birch (Betula alleghaniensis), sweet birch (B. lenta), yellow-poplar, hemlock (Tsuga spp.), basswood (Tilia spp.), northern red oak Quercus rubra), and butternut (Juglans cinerea). Understory vegetation includes black cherry, white ash (Fraxinus americana), sugar maple, beech (Fagus grandifolia), red maple (Acer rubrum), striped maple (A. pensylvanicum), witch-hazel (Hamamelis virginiana), hobblebush (Viburnum alnifolium), and other viburnums.
In the upland oak types throughout the East, cucumbertree is associated with white oak Quercus alba), red oak, black oak (Q. velutina), chestnut oak
(Q. prinus), yellow-poplar, elms (Ulmus spp.), hickories (Carya spp.), maples, blackgum (Nyssa sylvatica), white ash, basswood, yellow birch, and black cherry. Common understory species include dogwood (Cornus spp.), sassafras (Sassafras albidum), sourwood (Oxydendrum arboreum), serviceberry (Amelanchier arborea), viburnums, witch-hazel, grape (Vitis spp.), greenbrier (Smilax spp.), tick trefoil (Desmodium spp.), and hawthorn (Crataegus spp.).
In the Appalachian and Cumberland Mountains, cucumbertree commonly occurs with yellow-poplar, eastern hemlock (Tsuga canadensis), white ash, basswood, birches, sugar maple, northern red oak, black oak, and white oak. Common understory vegetation includes hemlock, sugar maple, beech, birch, rhododendron (Rhododendron spp.), viburnums, wild hydrangea (Hydrangea arborescens), and several ferns (Dyopteris spp.). At higher elevations in the central uplands oak types, cucumbertree is associated with yellow-poplar, white oak, northern red oak, black cherry, buckeye, white ash, beech, eastern white pine (Pinus strobus), and maples. Understory vegetation includes maples, oaks, hickory, black cherry, grape, spicebush (Lindera benzoin), wild hydrangea, viburnum, dogwood, and ferns.
At its southern limits in the Coastal Plains from Louisiana to west Florida, cucumbertree is associated with Sweetbay (Magnolia uirginiana), bigleaf magnolia (M. macrophylla), and southern magnolia (M. grandiflora) in addition to white oak, water oak (Quercus nigra), swamp chestnut oak Q. michauxii), and southern red oak (Q. falcata), elms, hickories, yellow-poplar, beech, maples, white ash, and blackgum.
Diseases and Parasites
Ambrosia beetles such as Platypus compositus, a common wood borer, seriously degrade recently felled trees during warm months. In the South, it is common to saw logs within 2 to 3 weeks after felling (2). The magnolia scale (Neolecanium cornuparuum), one of the largest scale insects in the United States, can seriously injure magnolia species. Other sap-sucking insects that attack cucumbertree are the European fruit lecanium (Parthenolecanium corni); the oleander pit scale (Asterolecanium pustulans); and the San Jose scale (Quadraspidiotus perniciosus). Common insect defoliators of cucumbertree are 0dontopus calceatus, Phyllocnistis magnoliella, and Phyllophaga forsteri (2).
Sapsucker damage is common on cucumbertree. Bird peck causes stain streaks in the wood several feet above and below each peck, resulting in lumber degrade.
Reaction to Competition
Life History and Behavior
Reproduction of cucumbertree in the forests is scarce because of the destruction of seeds by birds and rodents, high susceptibility of the seedlings to freezing, and the exacting conditions required for germination (18). Nursery practices used to artificially propagate magnolia seed include sowing the seed in the fall or stratifying the seed several months and then sowing the seed in the late winter or spring. The beds should be mulched and the mulch not removed until there is no possibility of a late spring frost. Young seedlings need half shade during most of the first summer in the seedbed. Normally plantings are done with 1-0 bare root seedlings (18). Cucumbertree is easy to transplant (30).
Seed Production and Dissemination
Flowering and Fruiting
Weather adversely influences the sensitive flower receptivity and available pollen. Also, cucumbertrees have a shorter period of receptivity and pollen shedding than other native magnolias (14).
Growth and Yield
Molecular Biology and Genetics
Statistics of barcoding coverage: Magnolia acuminata
Public Records: 0
Specimens with Barcodes: 1
Species With Barcodes: 1
IUCN Red List Assessment
Red List Category
Red List Criteria
National NatureServe Conservation Status
Rounded National Status Rank: N2 - Imperiled
Rounded National Status Rank: N5 - Secure
NatureServe Conservation Status
Rounded Global Status Rank: G5 - Secure
Relevance to Humans and Ecosystems
Cucumbertree is a valuable forest and shade tree, highly desirable for ornamental planting because of the showy flowers, fruits, and attractive foliage and bark (18). This species has been planted successfully well north of its native range (4); it grows well in slightly acid, well-drained soil (26).
Cucumbertree is used for wood products and resembles yellow-poplar except that the wood is heavier, harder, and stronger (3). This species is commonly used for lumber in the Appalachian Mountains, especially in West Virginia and adjoining States. The wood is usually sold as yellow-poplar; it has not been sold as cucumbertree lumber since 1928 (3). The wood is used in furniture, fixtures, venetian blinds, siding, interior trim, sashes, doors, boxes, and crates (10). Cucumbertree is not as desirable for fuelwood as the denser hardwoods. Compared with hickory, which has a fuel value of 100, cucumbertree has a fuel value of 57 (on a volume basis).
Cucumbertree has a specific gravity of 0.44 based on oven-dry weight and green volume, and 0.48 based on oven-dry weight and volume at 12 percent moisture content (27). Generally, the wood is close grained, durable, and susceptible to decay. Sapwood typically is a light color while the heartwood is pale brown. The branches of this species are soft and break easily, making tree climbing difficult (22).
Magnolia acuminata, commonly called the cucumber tree (often spelled as a single word "cucumbertree"), cucumber magnolia or blue magnolia, is one of the largest magnolias, and one of the cold-hardiest. It is a large forest tree of the Eastern United States and Southern Ontario Canada. It is a tree that tends to occur singly as scattered specimens, rather than in groves.
The cucumber tree is native primarily within the Appalachian belt, including the Allegheny Plateau and Cumberland Plateau, up to western Pennsylvania and New York. There are also numerous disconnected outlying populations through much of the southeastern U.S., and a few small populations in Southern Ontario. In Canada, the cucumber tree is listed as an endangered species and is protected under the Canadian Species at Risk Act. In 1993 The North American Native Plant Society purchased Shining Tree Woods to preserve a stand of Magnolia acuminata, which is also known as "The Shining Tree".
The leaves are deciduous simple and alternate, oval to oblong, 12–25 cm long and 6–12 cm wide, with smooth margins and downy on the underside. They come in two forms, acuminate at both ends, or moderately cordate at the base (these are usually only formed high in the tree).
Unlike most magnolias, the flowers are not showy. They are typically small, yellow-green, and borne high in the tree in April through June. The leaves of Magnolia acuminata are pointed at the tip and provide it with its name - 'acuminate' means tapering to a fine point. The name Cucumber Tree refers to the unripe fruit, which is green and often shaped like a small cucumber; the fruit matures to a dark red color and is 6–8 cm long and 4 cm broad, with the individual carpels splitting open to release the bright red seeds, 10-60 per fruit. The ripe fruit is a striking reddish orange color.
Uses and cultivation
Cucumber trees are excellent shade trees for parks and gardens, though they are not recommended for use as street trees. In cultivation, they typically only grow 15–20 m (50–75 feet) tall, although they reach over 30 m (100 feet) in ideal forest situations. They can become quite massive: the United States national (and most likely world) champion in Stark County, Ohio measures more than seven feet (2 m) in diameter (although only 79 ft or 24 m tall). They grow best in deep, moist, well-drained soils that are slightly acidic although they are tolerant of alkaline soils.
Magnolia acuminata has been used in hybridizing new varieties that share its yellow flower color and cold hardiness
- Sternberg, G., & Wilson, J. (2004). Native Trees for North American Landscapes. Portland, Oregon:Timber Press
- White, D.J. (2000). Update COSEWIC Status Report on the Cucumber Tree Magnolia acuminata in Canada. Committee on the Status of Endangered Wildlife in Canada. Ottawa, Ontario
Magnolia acuminata is of value to horticulturists because no other species of the genus has yellow tepals . Magnolia acuminata contains major quantities of xanthophyll lutein-5,6-epoxide and, in smaller amounts, acarotene-5,6-epoxide. Although this carotenoid occurs randomly throughout populations of M. acuminata , often it is masked by chlorophyll and not visibly expressed. Sometimes the carotenoid pigment shows through, as in the hybrid M. acuminata × M. denudata 'Elizabeth'. In that cross the M. acuminata parent tree was a nondescript plant with greenish flowers; yet out of this hybrid came 'Elizabeth', a stunning plant with light canary yellow flowers, a result completely unexpected. A thorough field study of M. acuminata is clearly warranted, and further investigation of the carotenoid flower pigments is needed to clarify the taxonomy of this widespread tree.
The largest known tree of Magnolia acuminata , 29.6m in height with a trunk diameter of 1.26m, is recorded from a specimen cultivated in Waukon, Iowa (American Forestry Association 1994).
The Cherokee and Iroquois tribes used Magnolia acuminata , largely the bark, as an analgesic, antidiarrheal, gastrointestinal aid, anthelmintic, toothache remedy, and for various other uses (D.E. Moerman 1986).