Index Seminum (Bratislava) 1837: . 1837.
Leaf blades 2–15 cm × 1–7+ mm. Phyllaries 10–20 mm. Ray corollas inconspicuous, laminae usually erect, sometimes spreading, 4–7 mm. Disc corollas 6–10 mm. Cypselae black, 4.5–9 mm; pappi (disc) of 5 outer scales 3–9 mm plus 5 inner scales 6–13 mm. 2n = 16.
Phenology: Flowering Mar–Jun.
Habitat: Grassy, often wet sites, usually with clay-rich soils
Elevation: 0–900 m
Calif., Oreg., Mexico (Baja California).
Achyrachaena mollis grows in low-elevation grasslands, savannas, and open woodlands throughout the California Floristic Province and occurs with vernal tarweeds of the genus Layia. During flowering, pappus scales of each disc floret form cylinders (imparting a honeycomb-like appearance to apices of heads); they are widely spread in fruiting heads. The species is self-compatible and is not known to hybridize with other tarweeds.