San Diego silverpuffs

Calaïs platycarpha A. Gray in War Department [U.S.], Pacif. Railr. Rep. 4(5): 113. 1857; Microseris platycarpha (A. Gray) Schultz-Bipontinus

Cypselae columnar to obconic, 3–4.5 mm (tapered to basal callosities, filled by embryos) ribs slightly flared apically; pappi of orbiculate to lanceolate, involute, arcuate (glabrous) scales 2.5–7 mm, 0.5–2 mm longer than cypselae. 2n = 18.

Flowering Mar–-May. Clay soil, mesa flats, hillsides, sometimes near vernal pools, grasslands, southern coastal scrub and Engelmann oak woodlands; 10–1100 m; Calif.; Mexico (Baja California).

Subspecies platycarpha is cited as severely declining in abundance because of urban development (D. P. Tibor 2001). It replaces subspp. tenella and douglasii in southwestern California and northern Baja California.