Citation: L., Sp. Pl. 987 (1753).

Derivation: Greek ambrosia, the unguent of the gods; used in Roman times as the name of various aromatic plants.

Synonymy: Not Applicable

Common name: Ragweeds.

Description:
Annual and perennial herbs, often somewhat woody, glandular, aromatic; leaves cauline, mostly opposite, petiolate or sessile, flat, lobed to bipinnate.

Capitula inconspicuous, unisexual, monoecious; male capitula discoid, numerous, drooping, in leafless terminal racemes; involucre cup-shaped, herbaceous, of few uniseriate almost completely connate bracts; receptacle with scales; florets tubular, pentamerous; anthers free, obtuse at the base, with a short appendage at the apex; style short, entire; female capitula sessile in the upper leaf axils; involucre vase-shaped, of few uniseriate almost completely connate bracts, becoming hardened, beaked and ribbed in fruit; floret solitary; corolla absent; style branches linear.

Achene ovoid, smooth, retained inside the nut-like involucre; pappus absent.

Distribution:  About 40 species in North and South America and the Mediterranean region; 3 are naturalised in Australia.

Biology: No text

Key to Species:

1. Leaves pinnatipartite, the segments lanceolate, often toothed, 2-4 mm wide	A. psilostachya 1.
1. Leaves bipinnatisect, the segments linear, to 1.5 mm wide	A. tenuifolia 2.

Author: Not yet available