Ambrosia chamissonis

(Lessing) Greene

Man. Bot. San Francisco, 188. 1894

Synonyms: Franseria chamissonis subsp. bipinnatisecta (Lessing) Wiggins & Stockwell A. chamissonis var. bipinnatisecta (Lessing) J. T. Howell
Basionyms: Franseria chamissonis Lessing
Treatment appears in FNA Volume 21. Treatment on page 16. Mentioned on page 11.
Perennials, 50–150(–350+) cm. Stems prostrate or decumbent. Leaves mostly alternate; petioles 15–30(–45+) mm; blades rounded-deltate to ovate or obovate, 20–45(–70+) × 10–25(–50+) mm overall, not lobed or 1–2(–3)-pinnately lobed, bases cuneate, ultimate margins entire or toothed, abaxial and adaxial faces strigillose to sericeous. Pistillate heads clustered, proximal to staminates; florets 1. Staminate heads: peduncles 0.5–2 mm; involucres shallowly cup-shaped, 4–6+ mm diam., strigillose; florets 8–25(–50). Burs: bodies fusiform to ± pyriform, 4–7+ mm, ± strigillose to pilosulous, spines 8–16+, scattered, stoutly conic or flattened- to triquetrous-subulate, 0.5–1.5+ mm, tips straight. 2n = 36.

Phenology: Flowering Apr–Nov.
Habitat: Sandy beaches and strand
Elevation: 0–10 m



B.C., Alaska, Calif., Oreg., Wash., Mexico (Baja California).




Lower Taxa

No lower taxa listed.