Hesperolinon congestum NatureServe Explorer Species Reports — NatureServe Explorer is a source for authoritative conservation information on more than 50,000 plants, animals and ecological communtities of the U.S and Canada. NatureServe Explorer provides in-depth information on rare and endangered species, but includes common plants and animals too. NatureServe Explorer is a product of NatureServe in collaboration with the Natural Heritage Network.
ITIS Reports — ITIS (the Integrated Taxonomic Information System) is a source for authoritative taxonomic information on plants, animals, fungi, and microbes of North America and the world.
FWS Digital Media Library — The U.S. Fish and Wildlife Service’s National Digital Library is a searchable collection of selected images, historical artifacts, audio clips, publications, and video.Hesperolinon congestum, or Marin dwarf flax, is an annual herb, which is known to occur only in San Mateo, San Francisco and Marin County, California, United States. This plant occurs chiefly on serpentine soils, especially in dry native bunch grasses, chaparral or other grasslands at elevations less than 200 meters. The flowers are congested at the tips of the dichotomously branching stems. H. congestum is in flower between April and July. The outlook for this plant depends on survival of only about twenty small colonies, most of which are not actively managed for protection, even though the species is federally and state-listed as threatened. This species is also less commonly known as Marin western flax.