Monographs Details:
Authority:

Acevedo-Rodríguez, Pedro & collaborators. 1996. Flora of St. John, U.S. Virgin Islands. Mem. New York Bot. Gard. 78: 1-581.
Family:

Asteraceae
Description:

Species Description - Erect annual herb, 0.5-1.5 m tall, moderately branched; stems glabrous to sparsely villous, especially villous at the nodes. Leaves simple or trifoliate (rarely pinnately or bipinnately compound), opposite, to 10 cm long; blades (when leaf simple) or leaflets 3- 6 X 1-3.7 cm, ovate, the apex acute to acuminate, the base attenuate to cordate or truncate, the margins serrate, the terminal leaflet essentially sessile; rachis (when present) to 1 cm long, commonly winged; petioles to 3 cm long. Inflorescence of few to many heads in terminal cymose clusters; peduncles 1-7 mm long, glabrous to sparsely villous. Heads radiate; involucre bell-shaped, generally not broadening greatly in fruit; outer involucral bracts 8-13, commonly spatulate, 3-4 mm long, the inner ones 8-10, ovate, 3-7 mm long. Ray flowers conspicuous, sterile, 5-8; corollas white. Disk flowers 20-65; corollas yellow, 3-5 mm long. Achenes usually straight, somewhat flattened to variously angled or ribbed, 4-13 mm long, glabrous to tuberculate-strigose; pappus of 2 awns, 1-2 mm long.

Discussion:

Common names: shepard's needle, Spanish needle.

Distribution:

South America| Central America| México Mexico North America| South America| Saint Croix Virgin Islands of the United States South America|