Malacothrix similis

W. S. Davis & P. H. Raven

Madroño 16: 262, fig. 2c. 1962.

Conservation concern
Treatment appears in FNA Volume 19. Treatment on page 320. Mentioned on page 311, 312.

Annuals, 5–30+ cm. Stems 1–11, erect or ascending, branched mostly proximally, glabrous or sparsely arachnose to puberulent and glabrescent. Cauline leaves: proximal mostly lance-linear, sometimes pinnately lobed, not fleshy, ultimate margins dentate or entire, faces glabrous or sparsely arachnose to puberulent and glabrescent; distal reduced subentire. Calyculi of 8–12+ lance-deltate to lanceolate bractlets, hyaline margins 0.05–0.3 mm wide. Involucres narrowly campanulate, 6–10 × 3–6 mm. Phyllaries 18–21+ in ± 2 series, lance-linear to linear, ± equal, hyaline margins 0.05–0.2 mm wide, faces glabrous. Receptacles not bristly. Florets 32–73: corollas yellow, 4–9 mm; outer ligules exserted 2–4 mm. Cypselae ± cylindro-fusiform to prismatic, 1.4–1.7 mm, ribs extending to apices, 5 more prominent than others; pappi persistent, of ca. 18, irregular needlelike teeth plus 1 bristle. Pollen mostly 4-porate (mean diam. 30 µm). 2n = 28.


Phenology: Flowering Apr–May.
Habitat: Coastal plains, beaches, dunes
Elevation: 0–40 m

Distribution

V19-485-distribution-map.gif

Calif., Mexico (Baja California).

Discussion

Of conservation concern.

Malacothrix similis has been collected on Santa Cruz Island (in 1888) and at Hueneme Beach (in 1925).

Selected References

None.

Lower Taxa

None.