The following Participating Institutions are custodians for this species in the CPC National Collection:
Santa Barbara Botanic Garden
The conservation of Calycadenia villosa is fully sponsored.
Dieter Wilken, Ph.D. contributed to this Plant Profile.
Dwarf Calycadenia is a summer-flowering annual up to 30 cm tall, with a basal rosette of many, grayish, simple leaves. Each plant can produce from 1 to 15 heads with 1-4 white to pinkish ray flowers and 10 to 15 disk flowers. Most populations are composed of plants with a single, simple to distally branched stem, but a few in San Luis Obispo County are shorter and have several ascending to spreading stems from the base. Prior to 1999, only 2 localities were documented, collectively composed of less than 1000 plants. Other reports were based on mis-identifications. Surveys conducted by the Santa Barbara Botanic Garden, however, have revealed at least 83 occurrences, all restricted to southern Monterey and northern San Luis Obispo counties. Most documented occurrences occur on Fort Hunter Liggett in Monterey County, California.
Distribution & Occurrence
Open sites or barren areas composed of sandy to fine-gravelly clay soils, often in oak savanna and grasslands, but sometimes on talus or rock outcrops in chaparral. Common associates include Lasthenia californica, Linanthus liniflorus, Micropus californicus, Lotus purshianus, and other spring-flowering annual dicots.
|At least 82 sites have been documented, of which about 70 have from 10 to 1,000 individuals in an average year. Another 10 occurrences support populations usually greater than 1,000 each. Censuses of plants have varied annually resulting from a positive correlation between winter precipitation and population size.|
Conservation, Ecology & Research
Competition from noxious weeds.
Loss of reproductive plants during human-cause fires.
Studies of the breeding system, seed dormancy and germination requirements, and other variables important to understanding ecological distribution.
Baldwin, B.G. 1993. Molecular phylogenetics of Calycadenia (Compositae) based on its sequences of nuclear ribosomal DNA: chromosomal and molecular evolution reexamined. American Journal of Botany. 80: 222-238.