|Santa Ynez false lupine, Santa Ynez goldenbanner|
|Hook. & Arn|
|Dieter Wilken, Ph.D.|
The following Participating Institutions are custodians for this species in the CPC National Collection:
Santa Barbara Botanic Garden
The conservation of Thermopsis macrophylla is fully sponsored.
Dieter Wilken, Ph.D. contributed to this Plant Profile.
Fewer than 2500 plants survive within a relatively narrow band about 3 miles long along the crest of the central Santa Ynez Mountains in Santa Barbara County, California. Current populations consist of plants similar in age and may be several decades old, because seeds germinate only after historically infrequent fires. Plants are the largest in the genus Thermopsis, are up to 1 meter wide, and are up to 2 meters tall when in full bloom. Leaves appear in the late winter, forming large clusters near the base. Each plant may produce up to 10 flowering stalks, each bearing between 90 and 100 flowers that are 2 cm long. (Chen et al. 1994)
Distribution & Occurrence
Open sites on gravelly to rocky substrates derived from sandstone at an altitude of 1000 - 1400 meters. Common chaparral associates include Adenostoma fasciculatum, Arctostaphylos glandulosa, and Ceanothus leucodermis. Populations occur on open sites that experience wet winters, hot summer days, and foggy summer nights.
|Single individuals and colonies consisting of 3-150 plants are dispersed as patches within a narrow, oblong area about 3 miles long. The number of plants are estimated to be between 2,000 and 2,500. A small disjunct population of less than 10 plants occurs about 15 miles distant in the same mountain range. Reports of other plants in the Santa Ynez Mountains have not been substantiated by recent surveys, and reports from other mountain ranges in California are based on misidentifications.|
Conservation, Ecology & Research
The seeds have exceptionally hard coats and do not germinate unless they have been scarified and/or heated to temperatures of 80 degrees Centigrade.
Plants are self-compatible, and are actively visited by bumblebees and carpenter bees (Wilken pers. obs.).
Each fruit produces a full complement of 6-8 seeds, which are dispersed passively. Because large plants often produce several inflorescences, each with as many as 100 flowers, a substantial seed bank can be expected in close proximity. However, Borchert (1989) found low rates of recruitment and establishment from seed during 8 years following a controlled burn.
Proposed 300-foot-wide fire break.
Potential perturbation of natural fire cycles.
Competition at seedling stage from annual exotic grasses.
Damage to plants by
Populations are monitored annually to estimate numbers, reproductive rates, and pollinator visitation.
Ecological factors determining successful establishment of plants from seeds.
A management plan that increases the number of plants and ensures stable population structure.
Borchert, M. 1989. Postfire Demography of Thermopsis macrophylla H & A var. agnina J.T. Howell (Fabaceae), a Rare Perennial Herb in Chaparral. American Midland Naturalist. 122, 1: 120-132.
Chen, C.J.; Mendenhall, M.G.; Turner, B.L. 1994. Taxonomy of Thermopsis (Fabaceae) in North America. Annals of the Missouri Botanical Garden. 81, 4: 714-742.