Species Spotlight: Thread-leaved Brodiaea

Thread-leaved brodiaea (Brodiaea filifolia) is one of 13 species of the genus Brodiaea, a genus largely restricted to California.  Due to habitat loss, this species is listed as threatened by the U.S. Fish and Wildlife Service and endangered by the CA Department of Fish and Wildlife. This plant is a perennial geophyte, meaning that the plant lives for multiple years and stores energy and water underground for part of the year in a bulb (like a tulip or daffodil). The brodiaea “bulb” or more accurately, corm, has a dark brown, fibrous tunic. The plant has long narrow leaves and a flowering stalk about 8-16 inches high. The flowers that appear in Spring are dark blue to violet in color.

On Rancho Mission Viejo thread-leaved brodiaea occur in two locations, one of which is already protected in the Nature Reserve. The other location will become part of the Nature Reserve in the future.  From studies of the plants in the Nature Reserve, we know that these plants are pollinated by native burrowing bees, sweat bees and flower-loving flies. These plants take several years to mature and only a fraction of mature individuals flower in any given year. Early season rains (Nov and Dec) are key to successful reproduction in this species. RMV has increased the number of brodiaea in the Nature Reserve by translocating populations from development areas and growing and planting nursery grown plants.