Heterotheca subaxillaris

Heterotheca subaxillaris, known by the common name camphorweed,^[3] is a North American species of flowering plant in the family Asteraceae.^[4]

Heterotheca subaxillaris
Conservation status
Secure  (NatureServe)[1]
Scientific classification
Kingdom:	Plantae
Clade:	Tracheophytes
Clade:	Angiosperms
Clade:	Eudicots
Clade:	Asterids
Order:	Asterales
Family:	Asteraceae
Genus:	Heterotheca
Species:	H. subaxillaris
Binomial name
Heterotheca subaxillaris (Lam.) Britton & Rusby 1887
Synonyms[2]
Synonymy Inula subaxillaris Lam. 1789 Calycium divaricatum Elliott Calycium scabrum Elliott Chrysopsis scabra (Pursh) Elliott Diplopappus scaber (Pursh) Hook. Heterotheca chrysopsidis DC. Heterotheca lamarckii Cass. Heterotheca scabra (Pursh) DC. Inula scabra Pursh Stelmanis scabra (Pursh) Raf.

Distribution

It is widespread across much of the United States (from California to Massachusetts) as well as Mexico and Belize.^[5][6]

Description

Heterotheca subaxillaris is a perennial, aromatic herb up to 203 centimeters (80 inches or 6 2/3 feet) in height, often with several erect stems. The stems are hairy to bristly. The inflorescence contains 3-180 flower heads in a flat-topped array. Each head contains 15–35; yellow ray florets surrounding 25–60 disc florets at the center.^[7]

Chemistry

The leaf volatiles from which the name "camphorweed" is derived include camphor, but as a minor constituent (less than 2%); of 41 documented volatiles, for example, caryophyllene, pinene, borneol, myrcene, and limonene each comprised over 5% of the total.^[8]