Artemisia annua is an annual herb, erect, much branched, 30 cm to 3 m tall; sweet smelling.

Artemisia annua. leaves. Natural Drugs. naturaldrugs.blogspot.com (Accessed 10/2017)
Leaves alternate, about 2-10 cm long, fern-like, two or three times pinnately divided, ultimate segments linear, margins toothed, persistent into winter.

Artemisia annua flower heads. Picture by Andrea Moro. Dipartimento di Biologia, Università di Trieste. Comune di Trieste, cantiere in Città Vecchia., TS, Friuli Venezia Giulia, Italia, – Image licensed under a Creative Commons Attribution Non Commercial Share-Alike 3.0 License (Accessed 10/2017).
Flowers pale greenish, very small, in compact heads that arise from a bract-covered base (receptacle), flowers tubular, radially symmetrical (disc flowers) only, heads 0.2 cm high, basal bracts membranous, rounded, nearly covering flowers, heads short-stalked, often nodding; inflorescence openly branched, leaves of inflorescence reduced; wind pollinated, Aug.-Nov.
Fruit dry, achenes.
Wetland status: FACU.
Frequency in NYC: Infrequent.
Origin: Eurasia.
Habitat: Open areas, fill soils.