This species belongs to subgenus Filifoliae, a group of Brodiaea species that do not reproduce vegetatively and instead rely solely on seed recruitment. This species is also self-incompatible and only a small percentage of the population reaches maturity in any given year (MSHCP WRC 2001). Morphological research and phenetic analysis has found B. santarosae to be a species unique from B. orcuttii and B. filifolia and their F1 hybrid offspring, which all look similar and occur in close proximity to one another (Chester et al 2007).

Based on an August 2020 extract of the California Plant Rescue Database, San Diego Zoo Global has collected 2 seed accessions of Brodiaea filifolia from 1 plant occurrences listed in the California Natural Diversity Database. These collections together emcompass 50 maternal plants

Based on an August 2020 extract of the California Plant Rescue Database, California Botanic Garden has collected 4 seed accessions of Brodiaea filifolia from 2 plant occurrences listed in the California Natural Diversity Database. These collections together emcompass 183 maternal plants

Endemic to southern California (Los Angeles, Orange, Riverside, San Bernardino, and San Diego counties). Populations are seriously threatened by ongoing, intensive development and by conversion to agriculture. In addition, this species is self-incompatible and requires pollination with plants that have different alleles at the incompatible locus.

Brodiaea filifolia was listed as threatened by the USFWS in 1998. A critical habitat plan was designated in 2005 and includes areas in Los Angeles and San Diego Counties (5 subunits total). This species is seriously threatened by urbanization and reside

The exact number of extant populations is difficult to assess for several reasons. Concepts of occurrences and populations have varied widely and have been reported very differently by different biologists. The Federal listing (FWS 1998) noted thirty-seven extant populations, however, with the discovery of Brodiaea santarosae there are now many mis-identified, and un-vouchered populations, potentially with more than one species occurring; and two populations recently added after it was confirmed that they were not of hybrid origin (Chester et al, 2007). Population counts are extremely hard to assess as in any given year only a small number of corms will have above-ground activity. In one instance only 20 individuals were seen, but during a transplanting effort more than 8,000 corms were found in the soil (MSHCP WRC 2001). Fewer than 500 individuals have been observed within half of the populations, and populations exceeding 5,000 flowering stalks have been reported in only six populations (MSHCP WRC 2001).

This species belongs to subgenus Filifoliae, a group of Brodiaea species that do not reproduce vegetatively and instead rely solely on seed recruitment. This species is also self-incompatible and only a small percentage of the population reaches maturity in any given year (MSHCP WRC 2001). Morphological research and phenetic analysis has found B. santarosae to be a species unique from B. orcuttii and B. filifolia and their F1 hybrid offspring, which all look similar and occur in close proximity to one another (Chester et al 2007).

Many populations exist on protected land, including three on federal land (Camp Pendleton); two on county government lands in Orange County (Caspers Regional Park and Aliso-Woods Canyon Regional Park); San Jacinto Wildlife Management Area in Riverside County; and the areas covered by the recent critical habitat designation in Los Angeles and San Diego counties. However, the largest population of observed individuals of B. filifolia occurs on private property in the city of San Marcos, San Diego County (USFWS 1998). There is no current recovery plan for this species, however its habitat requirements fall under the Vernal Pools of Southern California Recovery Plan: http://ecos.fws.gov/docs/recovery_plan/980903a.pdf

The recent description of Brodiaea santarosae means that previous population reports of B. filifolia need to be reviewed in light of this new species. Monitoring for populations is inherently difficult (see section Number Left above) and a definition of a population or occurrence should be determined for this species. Populations that were previously disced for fire suppression should be closely monitored for recovery. Population disturbance should be minimized at all sites. A recovery plan should be developed for this species, especially for areas that previously received severe impacts from fire management regimes.

Brodiaea orcuttii and B. filifolia have previously been established as sister taxa (closest relatives), however the position of this new species B. santarosae, and whether it is ancestral to the others or a product of polyploidy and/or hybrid introgression remains to be determined. A seedbank should be established to enable future restoration or revegetation efforts.