About Lessingia micradenia Greene
Lessingia micradenia is a rare species of flowering plant in the Asteraceae family, with the common name Mt. Tamalpais lessingia. It is endemic to the San Francisco Bay Area of California, where it grows in regions with serpentine soils. The species is split into two rare varieties, each with a restricted range on opposite sides of the Bay Area. Lessingia micradenia var. glabrata occurs at several sites across Santa Clara County, south of San Jose; Lessingia micradenia var. micradenia is only found at a small number of locations around Mount Tamalpais in Marin County.
This species is a slender erect annual herb. It varies in size from just a few centimeters to over half a meter in height, and produces spreading branches. Its texture is often hairy or woolly. Upper leaves are small, pointed, and no longer than 2 centimeters, while lower leaves are longer and wither early. The small flower heads grow singly or in clusters. Each flower head is lined with glandular phyllaries that have purple tips. The head is discoid, meaning it has no ray florets, and only contains a few funnel-shaped, lobed disc florets that range in color from light purple to nearly white. The fruit is an achene, with a pappus made of five distinct whitish points.
