Brodiaea santarosae
T. Chester, W. Armstrong & K. Madore
Santa Rosa Basalt Brodiaea
G1Critically ImperiledGlobal Rank
HighThreat Impact
Identity
Unique IDELEMENT_GLOBAL.2.814730
Element CodePMLIL0C0G0
Record TypeSPECIES
ClassificationSpecies
Classification StatusStandard
Name CategoryVascular Plant
Endemicendemic to a single state or province
KingdomPlantae
PhylumAnthophyta
ClassMonocotyledoneae
OrderAsparagales
FamilyAsparagaceae
GenusBrodiaea
Concept ReferenceChester, T., W. Armstrong, and K. Madore. 2007. Brodiaea santarosae (Themidaceae), a new rare species from the Santa Rosa basalt area of the Santa Ana mountains of southern California. Madroño 54(2): 187-198.
Taxonomic CommentsMost plants now assigned to this species were previously thought to be hybrids between Brodiaea orcuttii and Brodiaea filifolia. Chester et al. (2007) argue that these populations are a separate, distinct species rather than hybrids, because of (1) lack of sympatry between the three taxa, (2) "B. santarosae" plants have numerous characteristics that are not intermediate between the proposed parent taxa, and (3) true hybrids between Brodiaea orcuttii and Brodiaea filifolia, with the expected intermediate characteristics, appear to exist in San Marcos, CA, where the parent species overlap; these hybrids differ from "B. santarosae" plants (Chester et al. 2007).
Conservation Status
Rank MethodExpertise without calculation
Review Date2016-12-16
Change Date2016-12-16
Edition Date2016-12-06
Edition AuthorsGravuer, K., rev. R. Bittman (2016)
Threat ImpactHigh
Range Extent100-250 square km (about 40-100 square miles)
Number of Occurrences6 - 20
Rank ReasonsThis species is essentially restricted to the Santa Rosa Basalt rock formation in southwest Riverside County and immediately-adjacent San Diego County, California. There are 12 occurrences, of which 6 are historical. Threats not well known, but include development, altered hydrology, roads, and ORVs.
Range Extent CommentsSouthwest Riverside County and immediately-adjacent Miller Mountain of San Diego County, California. Occurs only on or very close to the 8-11 million-year-old Santa Rosa Basalt. Most of the known populations occur within a ~40 sq. km area; one additional population is disjunct from these by 11 km (Chester et al. 2007).
Occurrences CommentsThere are 12 mapped occurrences; 6 are historical and need rechecking (CNDDB 2016).
Threat Impact CommentsThreats not well known, but definitely include development, altered hydrology, roads, and ORVs (CNDDB 2016). Erosion of the Santa Rosa Basalt, to which this species appears restricted, is listed as a threat by Chester et al. (2007). It occurs at sites with abundant non-native grasses, but appears to co-exist stably with these species (Chester et al. 2007).
Ecology & Habitat
Diagnostic Characteristics
Distinguished from other Brodiaea species in southern California by its large flowers and distinctive, variable staminodes (Chester et al. 2007). Distinguishing flower and staminode features include: staminodes present in 90-100% of flowers, staminodes filiform or uniformly tapered from base to tip (vs. oblong to rectangular in outline, tapered only near tip if at all), filiments 2-8mm (vs. 0-1.5 mm), staminodes 0-7 mm long (vs. 1-4.5 mm), staminodes recurved to erect (vs. reflexed against perianth), perianth 24-36 mm (vs. 19-24 mm), style 10.5-17.0 mm (vs. 8-9.5 mm), ovary 3.5-8.2 mm (vs. 4-5 mm), anther 5.4-8.9 mm (vs. 5-5.5 mm) (Chester et al. 2007).
Habitat
All known populations grow in soils derived from the Santa Rosa Basalt rock formation. Open areas, often grasslands, sometimes in areas with abundant tall non-native grasses. Grows in a range of moisture conditions, from vernal pool edges to relatively dry sites. Can grow in disturbed soil on roadsides.
Terrestrial HabitatsGrassland/herbaceous
Palustrine HabitatsTEMPORARY POOL
Other Nations (1)
United StatesN1
| Province | Rank | Native |
|---|
| California | S1 | Yes |
Roadless Areas (1)
California (1)
| Area | Forest | Acres |
|---|
| Wildhorse | Cleveland National Forest | 1,483 |
References (3)
- Bittman, Roxanne. Personal Communication. Botanist, California Natural Diversity Database, Sacramento, Calif.
- California Natural Diversity Database (CNDDB). 2016. RareFind Version 5.1.1. California Department of Fish and Game, Sacramento.
- Chester, T., W. Armstrong, and K. Madore. 2007. <i>Brodiaea santarosae</i> (Themidaceae), a new rare species from the Santa Rosa basalt area of the Santa Ana mountains of southern California. Madroño 54(2): 187-198.