National Collection of Imperiled Plants

CPC National Collection Plant Profile

Photographer:

Valerie Soza

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CPC National Collection Plant Profile

Arenaria macradenia var. kuschei

Family:	Caryophyllaceae
Common Names:	Forest Camp sandwort, Kusche's sandwort
Author:	(Eastw.) Maguire
Growth Habit:	Perennial
CPC Number:	267

Distribution
Protection
Conservation
References

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Photographer: Valerie Soza

Arenaria macradenia var. kuschei is Not Sponsored

Primary custodian for this plant in the CPC National Collection of Endangered Plants is:

Rancho Santa Ana Botanic Garden

Valerie Soza contributed to this Plant Profile.

Arenaria macradenia var. kuschei

Arenaria macradenia var. kuschei is one of four recognized varieties of this species. This taxon was previously thought to occur in Inyo or San Bernardino County, and its habitat was previously reported as unknown in various treatments (Hickman 1993; Skinner and Pavlik 1994). Arenaria macradenia var. kuschei was previously only known from one vague collection, its type collection, in 1929 from "Forest Camp, Mohave Desert" and had not been relocated or observed again until 1994 (Ross and Boyd 1996). Several populations were recently discovered in 1994-1997 on Liebre Mountain in the Western Transverse Ranges of California (Boyd 1997). Arenaria macradenia var. kuschei is morphologically similar to another, more common variety, var. arcuifolia to the west, but differs in the formers densely stipitate-glandular inflorescence (peduncles, pedicels, and calyces).

Distribution & Occurrence

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State Range

California

Habitat

Decomposed granitic sunny openings among oak woodland or chaparral or low scrub, in areas of more gentle relief, 4000-5700 feet elevation.

Distribution

Summit of Liebre Mountains, above the western Mojave Desert, Western Transverse Ranges, Los Angeles County, California.

Number Left

Seven populations of Arenaria macradenia var. kuschei along the western summit of Liebre Mountain, a total of approximately 130 individuals.

Protection

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Global Rank:	G5T1	6/5/2006	Guide to Global Ranks
Federal Status:	SC	1/19/1996	Guide to Federal Status
Recovery Plan:	No

State/Area Protection

State/Area	Rank	Status	Date

Conservation, Ecology & Research

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Ecological Relationships

Unknown.

Threats

� The seven populations of Arenaria macradenia var. kuschei are highly restricted, small in size, and may be sensitive to stochastic change (Boyd 1997).
� Vegetation management activities on the Angeles National Forest have been proposed within the habitat for Arenaria macradenia var. kuschei, including "crush and burn" of vegetation (Ross and Boyd 1996).
� The majority of the populations are located within the vicinity of recreational or traffic areas, along roads or campsites, and may be impacted by road maintenance or off-highway vehicle activities (Boyd 1997; Soza 2000).

Current Research Summary

A common garden study of morphological variation in Kusche's sandwort has been carried out by Rancho Santa Ana Botanic Garden, 1999-present.

Four of the seven populations of Arenaria macradenia var. kuschei co-occur with var. arcuifolia, exhibiting an east-west trend with the number of var. kuschei individuals decreasing and the number of var. arcuifolia individuals increasing towards the east. Seeds were collected from both varieties from 6 of the populations of var. kuschei, germinated, and transplanted into one-gallon pots in the nursery to observe the ratios of glandular (var. kuschei) versus nonglandular (var. arcuifolia) progeny from a single parental type from each population. Offspring from a single parental type from a single population are exhibiting both glandular and nonglandular morphologies, calling into question the validity of the varietal status of Arenaria macradenia var. kuschei. Both varieties kuschei and arcuifolia are producing progeny of both phenotypes except the westernmost population of pure kuschei individuals and a population to the east of pure arcuifolia individuals. The number of kuschei-type (glandular) progeny produced from seed from the Liebre Mountain populations decreases as the populations move east and the number of arcuifolia-type (glabrous) progeny increases. No intergradation is apparent between the two varieties. The glandular phenotype appears to become locally fixed within those populations of Arenaria macradenia furthest west along the summit of Liebre Mountain. Arenaria macradenia var. kuschei may be a local form of var. arcuifolia, the result of a single gene segregating in the populations, rather than a distinct variety (Soza and Boyd pers. comm. 2000).

Current Management Summary

All seven populations are currently under the management of the USDA Forest Service, Angeles National Forest. This taxon is listed as a Forest sensitive species. In 1997, a conservation seed collection was taken from 6 of the 7 populations along the summit of Liebre Mountain and stored at the Rancho Santa Ana Botanic Garden Seed Program.

Research Management Needs

Further investigation is needed into the taxonomic merit of Arenaria macradenia var. kuschei, involving controlled crosses between individuals of var. kuschei from the westernmost population along Liebre Mountain and var. arcuifolia from Sawmill Mountain to the east.

Ex Situ Needs

References

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Books (Single Authors)

Allan, G.J.; Mistretta, O.; Tommerup, M.; Blassey, K.; Brown, W.J., Jr. 1995. A field guide to the rare plants of the Angeles National Forest. USDA Forest Service, Pacific Southwest Region, Angeles National Forest, in cooperation with Rancho Santa Ana Botanic Garden. 153p.

Andersen, B.A. 1996. Desert Plants of Utah. Utah State University Extension.

Skinner, M.W.; Pavlik, B.M. 1997. Inventory of rare and endangered vascular plants of California: Electronic Inventory Update of 1994, 5th edition. Sacramento: California Native Plant Society.

Books (Sections)

Kartesz, J.T. 1999. A synonymized checklist of the vascular flora of the U.S., Canada, and Greenland. In: Kartesz, J.T.; Meacham, C.A., editors. Synthesis of the North American Flora, Version 1.0. North Carolina Botanical Garden. Chapel Hill, NC.

Books (Edited Volumes)

David P. Tibor, Convening Editor. 2001 Inventory of Rare and Endangered Plants of California (sixth edition). Sacramento, CA: California Native Plant Society. 388p.

James C. Hickman, Editor. 1993 The Jepson manual: Higher plants of California. Berkeley: University of California Press. 1400p.

Journal Articles

Ross, T.S.; Boyd, S. 1996. Arenaria macradenia var. kuschei (Caryophyllaceae), re-collection of an obscure Californian taxon, with notes on known habitat and morphological variation. Crossosoma. 22, 2: 65-71.

Soza, V. 2000. Common garden study of morphological variation in Kusche's sandwort (Arenaria macradenia var. kuschei), a rare plant of southern California (Southern California Botanists Grants Program, Annual Progress Report). Crossosoma. 26, 1: 7-11.

Reports

Boyd, S. 1997. A preliminary survey of potential habitat for Kusche's sandwort (Arenaria macradenia var. kuschei), Saugus Ranger District, Angeles National Forest, California. Arcadia: Submitted to William J. Brown, Jr., USDA Forest Service, Angeles National Forest. p.10.

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This profile was updated on 3/4/2010