Astragalus brauntonii Parish

More info for the terms: seed, wildfire

A large population of Braunton's milkvetch (approximately 400 individuals) was
documented in 1985 between Gypsum and Coal canyons of the Santa Ana Mountains
after the 1982 Gypsum Canyon wildfire [30,36]. A prefire population count
was not made, and method of regeneration (from seed or by sprouting) was unknown.
Further research is needed on the fire ecology of Braunton's milkvetch.

Braunton's milkvetch
Braunton's milk-vetch

More info for the terms: caudex, forb, seed, shrub

This description provides characteristics that may be relevant to fire ecology, and is not meant for identification. Keys for identification are available [2,16,24].

Braunton's milkvetch is a short-lived (2-3 years) perennial forb that grows to 5 feet (1.5 m) tall. Due to Braunton's milkvetch's considerable size, woody caudex, and multiple stout erect stems, it can be mistaken for a shrub [29,36]. The inflorescence is a raceme with 36 to 60 flowers. Unlike other species in the genus, the flowers turn brown and papery and are not immediately shed after fading. The leaves are pinnately compound, with 25 to 33 leaflets [2,16,24]. The seeds of Braunton's milkvetch have a thick, hardened seed coat. Braunton's milkvetch can be distinguished from other perennial species of milkvetch by the woolly haired stems and 2-chambered seed pods [16,34]. Braunton's milkvetch has a thick taproot [36].

More info for the term: natural

Braunton's milkvetch is endemic to southern California, ranging from the central south coast of California to the north Peninsular Ranges of the Los Angeles Basin in Ventura, Los Angeles, and Orange counties. According to California Natural Diversity Database reports, there are 28 known locations of Braunton's milkvetch in Los Angeles and Orange counties. Braunton's milkvetch is limited to 4 general areas in the Santa Monica, San Gabriel and Santa Ana mountains and Simi Hills in the San Fernando Valley [7,8,16,34,36]. The Jepson Flora Project provides a distributional map of Braunton's milkvetch.

More info for the terms: caudex, cone, cover, crown fire, fire frequency, fire regime, forbs, forest, frequency, fuel, grassland, natural, scarification, seed, serotinous, severity, shrub, top-kill, tree

Fire adaptations: Braunton's milkvetch is a fire-adapted species. The thick seed coat requires scarification by fire or mechanical disturbance to germinate [29,36]. Although undocumented (as of 2006), Braunton's milkvetch may sprout from the caudex after top-kill. Further research is needed on Braunton's milkvetch's adaptations to fire.

FIRE REGIMES: Braunton's milkvetch occurs in a mediterranean climate, with mild winters and hot, dry summers [21]. Summer drought generates low fuel moistures, and Braunton's milkvetch habitats typically experience stand-replacing fires. The natural fire return interval for Braunton's milkvetch habitats is estimated to range from 20 to greater than 100 years, averaging 70 years [36].

Chaparral ecosystems, with natural fire return intervals of 50 to 80 years, usually experiences high-severity fires [25]. In fall, southern California typically experiences hot, dry "Santa Ana" winds that drive chaparral fires. Such fires can easily burn thousands of hectares, killing most aboveground vegetation [6]. Coastal sage scrub experiences fires of similar severity, but with shorter-frequency intervals of 20 to 25 years [40]. Abundant postfire growth of herbs and sprouting shrub species combined with a dry fire season can result in chaparral and coastal sage scrub reburns in only 1 to 2 postfire years. Short fire-return intervals may convert shrublands to annual grasslands [30].

Annual grassland: Since it is a community dominated by nonnative plants, annual grassland does not have a "natural" fire regime. The presettlement frequency of lightning ignitions in California grasslands is assumed to be similar to present fire ignition rates in annual grasslands, although fire size in California prairie was probably larger. Historically, California grasslands consisted of perennial grasses and forbs but most have been converted to annual nonnative grass species [15]. Nonnative grass dominants may influence the fire regime [14]. California annual grasslands characteristically support fast-moving wildfires. Annual grasses germinate, set seed, and die in a single season, quickly curing into flashy fuels. Grassland fire return intervals range from 4 to 20 years, depending on local climate and ignition sources [25].

Knobcone pine habitats experience a range of fire frequencies from 33 to 55 years. Variations in fire frequency depend on vegetation surrounding knobcone pine stands [39]. Knobcone pine is an obligate fire type with a strict closed-cone habit. This adaptation, along with the general absence of animal agents that might open cones, leaves the species dependent upon stand-replacing crown fire for reproduction. [38]. Knobcone pines have a short life span (<100 years) and rarely escape fire [18].

Tecate cypress forest: During the last century, Tecate cypress average fire return interval was 25 years, with a range of 15 to 63 years [1,39]. However, Keeley [20] estimated natural fire frequency from 50 to 100 years for Tecate cypress communities based on reproductive rate data [1,10,41]. Tecate cypress is a fire-adapted tree species. It occurs in areas with extensive shrub cover and high probability of large crown fires. Mature trees die while fire releases the seeds within the serotinous cones. Tecate cypress begins producing cones at 10 years and reaches maximum cone production at 50 years. Fire return intervals less than 10 years could destroy populations and fire return intervals less than 50 years could reduce the number of seeds available for repopulation [18,30,42].

FIRE REGIMES: The following table provides fire return intervals for plant communities and ecosystems where Braunton's milkvetch is important. 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".

Community or ecosystem Dominant species Fire return interval range (years) California chaparral Adenostoma and/or Arctostaphylos spp. <35 to <100 California annual grasslands Avena, Bromus. and/or Hordeum spp. 4-20 coastal sagebrush Artemisia californica 25] pine-cypress forest Pinus-Cupressus spp. 9-63 [1,32,39]

More info for the terms: fuel, nonnative species, seed

Active management of potential habitat for Braunton's milkvetch should be considered. The use of prescription fire would probably increase population numbers by inducing germination of seeds from the seed bank. Construction of fuel breaks and firelines by heavy equipment should be avoided because it may disturb the soil seed bank as well as encourage the spread of nonnative species [12].

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More info for the term: hemicryptophyte

RAUNKIAER [26] LIFE FORM:
Hemicryptophyte

Braunton's milkvetch is endemic to carbonate soils of the foothills of the southern California mountains. It commonly occurs in disturbed chaparral, coastal sage scrub, and closed-cone forests at elevations of 50 to 2,000 feet (15-610 m). Soil requirements of Braunton's milkvetch contribute to its limited distribution [7,16,24,29,33,36].

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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):

More info for the term: cover

SAF COVER TYPES [11]:




248 Knobcone pine

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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

ECOSYSTEMS [13]:




FRES34 Chaparral-mountain shrub

FRES42 Annual grasslands

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

KUCHLER [23] PLANT ASSOCIATIONS:





K033 Chaparral

K035 Coastal sagebrush

K048 California steppe

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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 terms: cover, grassland, shrub

SRM (RANGELAND) COVER TYPES [28]:




205 Coastal sage shrub

206 Chamise chaparral

215 Valley grassland





HA

To date (2006), literature documenting fire's immediate effect on Braunton's milkvetch is lacking. It is mostly likely top-killed by fire.

Braunton's milkvetch is a source of nectar for megachilid bees and bumble bees [12,36]. Research is needed on other possible plant-animal relationships.

Palatability/nutritional value: The palatability of Braunton's milkvetch is undocumented at the time of this write-up. Some Astragalus species are toxic to livestock [3,24]

More info for the terms: forest, grassland, shrub

BITAT TYPES AND PLANT
COMMUNITIES:




Braunton's milkvetch is limited to carbonate soils (limestone outcrops) in
chaparral, coastal sage scrub, closed-cone forest, and grassland
communities of the southern California mountains [7,16,33,36].

Chaparral
shrub species associated with Braunton's milkvetch include chamise (Adenostoma fasciculatum),
red shank (A. sparsifolium), manzanita (Arctostaphylos spp.),
ceanothus (Ceanothus spp.), laurel sumac (Malosma laurina),
and sumac (Rhus spp.). California sagebrush (Artemisia
californica), California buckwheat (Eriogonum fasciculatum), and woolly
sunflower (Eriophyllum lanatum var. obovatum) dominate southern
coastal sage scrub communities where Braunton's milkvetch occurs. Black sage (Salvia
mellifera), purple sage (S. apiana), chaparral yucca (Yucca
whipplei), and golden-yarrow (Eriophyllum confertiflorum var.
confertiflorum) are common shrub species associates [9,25].

Braunton's milkvetch inhabits closed-cone forests of knobcone pine (Pinus
attenuata) and Tecate cypress (Cupressus forbesii). Chamise, ceanothus, and manzanita are common
chaparral shrub species associated with
close-coned pine-cypress forests. Many species of oaks (Quercus
chrysolepis, Q. vaccinifolia, Q. wislizenii) and pines (P.
coulteri, P. radiata) are associates in knobcone pine forest with
Braunton's milkvetch. California buckwheat, Parry's beargrass (Nolina
parryi), scrub oak (Quercus berberidifolia), and heart-leaved pitcher
plant (Lepechinia cardiophylla) are common
species associated with Braunton's milkvetch in Tecate cypress forests [17,18,27,39].

Nonnative grasses such as oat (Avena spp.), brome (Bromus spp.)
barley (Hordeum spp.), and rattail sixweeks grass (Vulpia myuros) dominate
the annual grasslands of California where Braunton's milkvetch is located
[22]. Common native grass associates are purple needlegrass (Nassella pulchra)
and other needlegrass (Stipeae) species [4].

More info for the term: forb

Forb

More info for the terms: forest, interference, seed, shrubs

Braunton's milkvetch is often found on disturbed sites and therefore is likely to have a
low tolerance for shade and growth interference from other plant species. Removal of shrubs and nonnative
species with minimal soil disturbance near known Braunton's milkvetch soil seed
bank locations may encourage establishment of new populations [12].



Braunton's milkvetch habitat is threatened by private and urban development.
Much of the suitable habitat for Braunton's milkvetch occurs on privately owned
land and is at risk for destruction. Braunton's milkvetch has not been found on
National Forest System lands, but potential habitat is protected [34,36].

No information is available on this topic.

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Braunton's milkvetch blooms from March to July [33].

More info for the terms: caudex, low-severity fire, wildfire

Seeds of Braunton's milkvetch germinate in response to fire. Braunton's milkvetch has a woody caudex that could allow for vegetative regeneration following low-severity fire. Populations have increased dramatically following wildfire events [12,30,36].

More info for the term: ground residual colonizer

POSTFIRE REGENERATION STRATEGY [31]:
Ground residual colonizer (on-site, initial community)

More info for the terms: bisexual, caudex, monoecious, scarification, seed

Braunton's milkvetch reproduces sexually [16,24], and may also sprout from the caudex [36].

Breeding system: Braunton's milkvetch is monoecious, with bisexual flowers [16,24].

Pollination: Native megachilid bees and bumble bees pollinate Braunton's milkvetch [12,36]. Ants may also play a role in pollination [12].

Seed production: No information is available on this topic

Seed dispersal: Braunton's milkvetch seeds do not have an apparent dispersal mechanism. Seeds most likely rely on water and gravity for dispersal [12].

Seed banking: Braunton's milkvetch's thick seed coat allows seeds to remain dormant in the soil seed bank for many years [36].

Germination: The seed coat of Braunton's milkvetch requires heat or mechanical scarification for germination. Scarification associated with disturbance increases germination success. Types of disturbance affecting the seed coat include expansion effects from wetting and drying, microbial degradation, heat from fire, and physical abrasion by soil movement [12]. In a germination experiment, Fotheringham and Keeley [12] scarified Braunton's milkvetch seeds by exposure to heat or seed coat penetration, and obtained germination rates of 80 % or greater. Other germination studies on Braunton's milkvetch resulted in 60 % germination of heat-treated seeds and only 1% germination without heat (Carroll, M. 1987 as cited in [36]).

Seedling establishment/growth: Because Braunton's milkvetch is a postdisturbance pioneer species, an open, light-intensive environment is most likely needed for seedling establishment and growth. In laboratory experiments, establishment of Braunton's milkvetch seedlings was greater in full sun and on limestone soils than in other environmental conditions and soil types [12]. Braunton's milkvetch seedlings are low growing when 1st established, then develop into larger, more erect plants within the 1st year [2].

Asexual regeneration: Information on asexual regeneration for Braunton's milkvetch is undocumented. Braunton's milkvetch has a woody caudex that may allow for asexual regeneration [36].

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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):

BLM PHYSIOGRAPHIC REGIONS [5]:




3 Southern Pacific Border

(key to state/province abbreviations)
UNITED STATES CA

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Braunton's milkvetch is an early seral species, appearing immediately following fire or disturbance. It lives for 2 to 3 years before senescing or being crowded out by later-succession vegetation [29].

The scientific name of Braunton's milkvetch is Astragalus brauntonii
Parish. (Fabaceae) [16,19,24].

Endangered [37]

Brachyphragma brauntonii (Parish) Rydberg
Astragalus Brauntonii Parish, Bull. So. Calif. Acad. 2: 26. 1903.
A perennial; stem erect, 1-1.5 mm. high, densely white-woolly; leaves 1-2 dm. long, spreading; stipules scarious, yellowish, lance-subulate, long-attenuate, about 1 cm. long; leaflets 25-35, oblong or elliptic, 1-2.5 cm. long, 3-10 mm. wide, white-villous on both sides, rounded and apiculate at the apex; peduncles 2-6 cm. long; racemes at first short and dense, in age elongate, 3-12 cm. long; bracts subulate, about 1 cm. long; pedicels very short; flowers reflexed; calyx white-villous, the tube 3-4 mm. long, gibbous at the base, 3 mm. broad, the teeth subulate, 3 mm. long; corolla pink, 1 cm. long; banner broadly obovate, moderately arcuate, the margins reflexed; wings shorter, the blade broadly oblong, with a very large reflexed basal auricle; keel-petals still shorter, the blade broad, almost cuneate, rounded at the apex, with a small auricle; pod reflexed, leathery, oblong-ovoid, 1 cm. long, 3 mm. wide and as thick, whitevillous, the upper suture slightly arcuate upwards, the lower deeply sulcate and strongly arcuate, the base rounded-cordate, the apex abruptly acute.
Type locality: Santa Monica, California.
Distribution: Southern California.

Perennial, Herbs, Stems woody below, or from woody crown or caudex, Taproot present, Nodules present, Stems erect or ascending, Stems less than 1 m tall, Stems 1-2 m tall, Stems hollow, or spongy, Stems or young twigs sparsely to densely hairy, Stems hairs pilose or spreading, Stems silvery, canescent, tomentose, cobwebby, or wooly, Leaves alternate, Leaves petiolate, Stipules conspicuous, Stipules membranous or chartaceous, Stipules persistent, Stipules free, Leaves compound, Leaves odd pinnate, Leaf or leaflet margins entire, Leaflets opposite, Leaflets 10-many, Leaves hairy on one or both surfaces, Inflorescences spikes or spike-like, Inflorescence axillary, Bracts very small, absent or caducous, Flowers zygomorphic, Calyx 5-lobed, Calyx glabrous, Petals separate, Corolla papilionaceous, Petals clawed, Petals pinkish to rose, Petals re ddish brown, maroon, Banner petal narrow or oblanceolate, Wing petals narrow, oblanceolate to oblong, Wing tips obtuse or rounded, Keel petals auriculate, spurred, or gibbous, Keel tips obtuse or rounded, not beaked, Stamens 9-10, Stamens diadelphous, 9 united, 1 free, Filaments glabrous, Style terete, Style persistent in fruit, Fruit a legume, Fruit stipitate, Fruit freely dehiscent, Fruit oblong or ellipsoidal, Fruit fleshy, Fruit exserted from calyx, Fruit enclosed in calyx, Fruit beaked, Fruit hairy, Fruit 3-10 seeded, Seeds cordiform, mit-shaped, notched at one end, Seed surface smooth, Seeds olive, brown, or black.

Astragalus brauntonii (lat. Astragalus brauntonii) — paxlakimilər fəsiləsinin gəvən cinsinə aid bitki növü.

Astragalus brauntonii is a rare species of milkvetch known by the common name Braunton's milkvetch. It is endemic to California, where it is known from fewer than 20 extant occurrences in the hills and mountains surrounding the Los Angeles Basin in Southern California. This is a federally listed endangered species in the United States.

Astragalus brauntonii es una especie de planta herbácea perteneciente a la familia de las leguminosas. Se encuentra en California en Estados Unidos.​

Astragalus brauntonii est une espèce végétale de la famille des Fabaceae. Cette espèce est endémique des États-Unis.

Astragalus brauntonii adalah spesies tumbuhan yang tergolong ke dalam famili Fabaceae. Spesies ini juga merupakan bagian dari ordo Fabales. Spesies Astragalus brauntonii sendiri merupakan bagian dari genus Astragalus. Nama ilmiah dari spesies ini pertama kali diterbitkan oleh Parish.

Astragalus brauntonii là một loài thực vật có hoa trong họ Đậu. Loài này được Parish miêu tả khoa học đầu tiên.