Arenaria macradenia var. kuschei
|Forest Camp sandwort, Kusche's sandwort|
The following Participating Institutions are custodians for this species in the CPC National Collection:
Rancho Santa Ana Botanic Garden
The conservation of Arenaria macradenia var. kuschei is fully sponsored.
Valerie Soza contributed to this Plant Profile.
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
Decomposed granitic sunny openings among oak woodland or chaparral or low scrub, in areas of more gentle relief, 4000-5700 feet elevation.
|Seven populations of Arenaria macradenia var. kuschei along the western summit of Liebre Mountain, a total of approximately 130 individuals.|
Conservation, Ecology & Research
Vegetation management activities on the Angeles National Forest have been proposed within the habit
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).
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 Bot
Andersen, B.A. 1996. Desert Plants of Utah. Utah State University Extension.