Desert Bitterbrush

desert bitterbrush

Mojave antelope brush

More info for the term: cover

Upright growth forms of desert bitterbrush provide cover for game animals [24].

More info for the term: shrub

Desert bitterbrush is a native evergreen shrub [22,24,26,28,30] that grows from 1 to 15 feet tall (0.3-4.5 m), depending on environmental conditions [28,47].

Desert bitterbrush is a deeply rooted species, with a taproot sometimes exceeding 16 feet (4.8 m) [16,28,] and very few shallow, lateral roots [21]. Because of its taproot, desert bitterbrush is drought tolerant [16,24,25].

Given sufficient moisture, desert bitterbrush is capable of producing nitrogen-fixing root nodules, although this response is not consistent [27,33,34].

Note: Desert bitterbrush has many botanical and ecological characteristics in common with antelope bitterbrush (Purshia tridentata), on which much more research has taken place. Please refer to that FEIS species summary for more general information about the genus.

Desert bitterbrush occurs in southern California, Arizona, southern Nevada, and Utah [12,23].

More info for the terms: fuel, tree

Desert bitterbrush recovers from fire by sprouting from undamaged root crowns below the soil surface and by establishing from seeds cached by rodents [6,7,8,28,45].

FIRE REGIMES of the California singleleaf pinyon-California juniper woodlands in which desert bitterbrush appears are dominated by long-interval canopy fires and slow recovery [44]. Fires in desert bitterbrush habitats probably were infrequent, since fuel in sagebrush-bitterbrush and juniper-bitterbrush communities tends to be light. In decadent stands, extremely dry and windy conditions can cause a severe fire [32].

To learn more about the FIRE REGIMES in communities in which desert bitterbrush appears, refer to the FEIS summary for associated species, such as big basin sagebrush, redberry juniper (Juniperus erythrocarpa), Gambel oak, Joshua tree, singleleaf pinyon, and California juniper, under "FIRE ECOLOGY OR ADAPTATIONS."

Fall mortality of desert bitterbrush following fire is higher than after spring burns [6,7,18].

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More info for the term: phanerophyte

Phanerophyte

Desert bitterbrush grows from 900 to 10,000 feet (700-3000 m) throughout its range [8,15,28,37,38,47].

Desert bitterbrush grows on a wide variety of soils, both alkaline and acidic [28,29]. Desert bitterbrush requires excellent drainage [15] and dominates on relatively young to very deep, coarse-textured, and well-drained soils. Desert bitterbrush grows particularly well on granitic alluvial fans, pumice or cinder deposits, or well-leached deposits of old lakebeds. The plant is able to survive on very harsh sites with little soil and high insolation. Desert bitterbrush performs most poorly on clay soils or on soils with a clay pan within 2 feet (61 cm) of the surface [28].

Desert bitterbrush grows in areas with around 10 inches (254 mm) annual precipitation [37], typically drier sites than those that support antelope bitterbrush. The plant is intolerant of frequent summer water [15].

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This species is known to occur in association with the following cover types (as classified by the Society of American Foresters):

209   Bristlecone pine

238   Western juniper

239   Pinyon-juniper

243   Sierra Nevada mixed conifer

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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):

More info for the term: shrub

FRES29   Sagebrush

FRES30   Desert shrub

FRES33   Southwestern shrubsteppe

FRES34   Chaparral-mountain shrub

FRES35   Pinyon-juniper

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This species is known to occur in association with the following plant community types (as classified by Küchler 1964):

More info for the term: woodland

K023   Juniper-pinyon woodland

K024   Juniper steppe woodlands

K037   Mountain-mahogany-oak scrub

K038   Great Basin sagebrush

K039   Blackbrush

K040   Saltbush-greasewood

K041   Creosotebush

K042   Creosotebush-bursage

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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: woodland

210   Bitterbrush

211  Creosotebush scrub

212  Blackbush

401  Basin big sagebrush

402  Mountain big sagebrush

412  Juniper-pinyon woodland

413  Gambel oak

415  Curlleaf mountain-mahogany

416  True mountain-mahogany

417  Littleleaf mountain-mahogany

421  Chokecherry-serviceberry-rose

504  Juniper-pinyon pine woodland

509  Transition between oak-juniper woodland and mahogany-oak association

More info for the term: fire tolerant

Desert bitterbrush is considered fire tolerant [1,22,29]. Plants sprout in response to being top-killed, but can be killed if heat is sufficient to kill the root crowns [10,18,45].

Desert bitterbrush is an important forage species for livestock, deer, and pronghorn [8,16,35,48], especially in winter [30].

More info for the terms: cover, forbs, shrub, shrubs, tree

Desert bitterbrush is found in several semi-arid shrub types throughout its range, including blackbrush (Coleogyne ramosissima),
Joshua tree (Yucca brevifolia), chaparral, and singleleaf pinyon (Pinus monophylla)-California juniper (Juniperus californica) woodlands [8,15,47].



In California, desert bitterbrush is commonly found with basin big sagebrush Artemisia tridentata ssp. tridentata), blackbrush, singleleaf pinyon, and California juniper. It also occurs with Joshua tree, creosote bush (Larrea tridentata), honey mesquite (Prosopis glandulosa), Stansbury cliffrose, and Great Basin bristlecone pine (Pinus longaeva). Shrubs often form more than 90% of the cover in desert bitterbrush stands. Perennial grasses are a minor element, and forbs are even less important [28].



In Nevada, desert bitterbrush is a component of the mountain brush community with snowberry (Symphoricarpos spp.), antelope bitterbrush, Stansbury cliffrose, mountain-mahogany (Cercocarpus spp.), Gambel oak (Quercus gambelii), Juneberry (Amelanchier pallida), wild crab apple (Peraphyllum ramosissima), and chokecherry (P. virginiana).




In the San Gabriel Mountains of California, desert bitterbrush occurs in the sagebrush scrub community with basin big sagebrush, Joshua tree, single-leaf pinyon, rubber rabbitbrush (Chrysothamnus nauseosus), spiny horsebrush (Tetradymia spinosa), Nevada broomsage (Lepidospartum latisquamum), beavertail prickly-pear (Opuntia basilaris), shadscale (Atriplex confertifolia), and fourwing saltbush (A. canescens) [14].

More info for the term: shrub

Shrub

Desert bitterbrush is browsing tolerant [30].

More info for the term: shrub

Crude protein content of desert bitterbrush is 9.0% [46]. Because desert bitterbrush is an evergreen shrub, its winter protein levels are generally higher than those of antelope bitterbrush and other deciduous forage [25].

AZ    CA    NV    UT

In Utah, desert bitterbrush is generally of medium palatability to livestock and wildlife [22].



In California, palatability of desert bitterbrush is ranked excellent to good for domestic sheep, domestic goats, and deer, fair for cattle, and fair to useless for horses [35].



Desert bitterbrush is less palatable to deer than its close relative, antelope bitterbrush [12,30].

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More info for the terms: fruit, seed

Initial growth of desert bitterbrush in southern Arizona begins in late February, yet seed does not mature until early June. In Utah, desert bitterbrush flowers in May and fruit matures by mid-July at low elevations and mid-August at high elevations [4].

Phenological development of desert bitterbrush grown in an experimental plot in Boise, Idaho, was as follows [36]:

Stage Date Leaf growth initiated April 26 First leaf expanded May 18 Floral buds visible April 28 Anthesis May 25 Fruit development initiated May 28 Leader growth initiated May 20 Fruit mature July 18

More info for the terms: layering, presence, seed

Desert bitterbrush often sprouts vigorously following fire [6,8,28], even in dry conditions [7]. Even root crowns charred below the surface have sprouted [28]. In some studies, however, desert bitterbrush has been killed by fire [10,18,45]. The fire literature does not specify whether the decumbent or erect form of desert bitterbrush is more susceptible to fire.

Stem layering is another response to fire if heat has not killed all aboveground tissue. Layering following fire is particularly evident on burned-over areas with finer-textured rather than coarse-textured soils [28].

Following spring prescribed burns near Ely, Nevada, mean rodent desert bitterbrush seed cache densities were significantly (p=0.05) higher within the burned areas than outside. Only 2 desert bitterbrush sprouted following these prescribed burns, and they lacked vigor and died the spring following the fires. The presence of large numbers of rodent caches may result in the continued presence of desert bitterbrush on the site [45].

More info for the terms: adventitious, fire regime, ground residual colonizer, root crown, shrub

Tall shrub, adventitious-bud root crown
Small shrub, adventitious bud/root crown
Ground residual colonizer (on-site, initial community)
Initial-offsite colonizer (off-site, initial community)

FIRE REGIMES:
Find fire regime information for the plant communities in which this species may occur by entering the species name in the FEIS home page under "Find FIRE REGIMES".

More info for the terms: layering, phenotype, root crown, seed

Desert bitterbrush regenerates by sprouting from the root crown, by stem layering, and by seed [29,37].

Seed crops are inconsistent, and germination and seedling establishment is extremely low [24,28,36,48]. Flowers are insect-pollinated and self-incompatible [36]. Seed production usually does not occur in plants younger than 10 years old [28]. Due to the large, heavy seed, desert bitterbrush is dependent on rodents and other agents for seed dispersal [10,28]. Seeds are dormant due to a hard seedcoat [9,28,48,49]. Dormancy can be overcome by stratifying seed from 5 to 6 weeks at 41 °Fahrenheit (40.5 oC). In 1 California study, Nord [28] found that seed remaining in the ground for more than 1 season rarely germinated. But in another study in Bishop, California, 60% of desert bitterbrush seeds germinated after 25 years of uncontrolled storage. Germination percentage in that study reached a high of 86% after 3 years of storage [39,40].

Stem layering is common among desert bitterbrush plants, particularly when environmental conditions (particularly high elevation) or phenotype result in a prostate life form [28].

Desert bitterbrush may also regenerate from roots severed below the soil surface, even up to 10 feet deep [28].

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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):

  3   Southern Pacific Border

  4   Sierra Mountains

  6   Upper Basin and Range

  7   Lower Basin and Range

12   Colorado Plateau

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Desert bitterbrush is a pioneer species on some extremely eroded and volcanic rock sites [28], and a mid-seral species on moderate sites. Following fire in blackbrush-dominated sites, desert bitterbrush precedes blackbrush for at least 28 years [2,5].

Desert bitterbrush is not shade tolerant [15].

The fully documented scientific name of desert bitterbrush is Purshia glandulosa Curran (Rosaceae) [17,47]. Desert bitterbrush appears to be a hybridization of Stansbury cliffrose (P. mexicana var. stansburiana) and antelope bitterbrush (P. tridentata) [26,28,42,47].



Desert bitterbrush hybridizes with Stansbury cliffrose, antelope bitterbrush [19,22,26,28], and possibly Apache-plume (Fallugia paradoxa) [30].

More info for the term: seed

Due to its ability to layer from dormant buds along the stem, desert bitterbrush is an excellent soil stabilizer [16,22,28,30]. Desert bitterbrush is useful for stabilizing soils where annual precipitation averages 11 inches (279 mm) or more [29]. With appropriate seed treatment, desert bitterbrush establishes well on disturbed sites either by seed or from transplants [29]. However, seeding can be difficult due to the dormancy of desert bitterbrush seed [48]. Desert bitterbrush can be propagated from stem cuttings. Cuttings should be collected in early spring or in August and September and treated with 0.8 to 2.0 IBA powder [16].

Purshia glandulosa Curran, Bull. Calif. Acad. 1: 153. 1885
Kunzia glandulosa Greene, Pittonia 2: 299. 1892.
Purshia tridentata glandulosa M. E. Jones, Proc. Calif. Acad. II. 5: 680. 1895.
Shrub 1-3 m. high, with brown or gray bark; leaves 5-10 mm. long, slightly tomentose when young, but green and glabrate in age, conspicuously glandular-punctate on the margin, 3-cleft (rarely 5-cleft) at the apex, with linear-oblong divisions; flowers solitary, short-pedicelled; hypanthium funnelform, tomentulose, 5 mm. long; sepals elliptic, 3 mm. long, rounded at the apex; petals yellow, spatulate, 5-6 mm. long; fruit narrowly fusiform, with the style 15 mm. long; seeds flesh-colored.
Type locality: Mohave side of Tehachapi Pass, California. Distribution: Southern California and Nevada.

Purshia glandulosa is a species of flowering plant in the rose family known by the common names antelope bitterbrush, desert bitterbrush, Mojave antelope brush.