Heterotheca Explained

Heterotheca (common names goldenasters, camphorweed, or telegraph weed) is a genus of North American plants in the family Asteraceae.[1]

Etymology

Heterotheca comes from Ancient Greek Greek, Ancient (to 1453);: ἕτερος "other, different" and Greek, Ancient (to 1453);: θήκη "case, chest", and refers to the fact that, in some species in the genus, the cypselae (achenes containing seed) of the disk and ray florets have different shapes.[2]

Etymology:The genus “Heterotheca” (Heterothe'ca:) is derived from the Greek heteros, “different,” and theke, “ovary,” from the unlike cypselas of the ray and disk florets.

https://southwestdesertflora.com/WebsiteFolders/All_Species/Asteraceae/Heterotheca%20subaxillaris,%20Camphorweed.html

Description, biology

These are annual and perennial herbs bearing daisy-like flower heads with yellow disc florets and usually yellow ray florets, associated with mesic to xeric habitats across North America. Several species now included in Heterotheca were previously classified in the genus Chrysopsis

Heterotheca species are often used as food plants by the larvae of some Lepidoptera species including Schinia lynx, Schinia nubila and Schinia saturata (all of which have been recorded on Heterotheca subaxillaris).

Chemistry

The leaf volatiles from which the name "camphorweed" is derived include camphor, but as a minor constituent (less than 2%); of the 41 documented volatiles in a study of Heterotheca subaxillaris, for example, caryophyllene, pinene, borneol, myrcene, and limonene each comprised over 5% of the total.[3]

Species

Sources:

Formerly included

Many species have been included in Heterotheca at various times in the past, but now regarded as more suitable for other genera. The most common of these is Chrysopsis, but others include Aster Bradburia Osbertia Munnozia Pityopsis + Tomentaurum.

External links

Notes and References

  1. https://www.biodiversitylibrary.org/page/4439620#page/143/mode/1up Cassini, Alexandre Henri Gabriel de. 1817. Bulletin des Sciences, par la Societe Philomatique 1817: 137
  2. Web site: US Wildflower - Camphorweed, Camphor Weed, False Goldenaster - Heterotheca subaxillaris . US Wildflowers . Gerald . C. Williamson . 2016 . 16 July 2016 .
  3. Lincoln . D.E. . B.M. . Lawrence . 1984 . The volatile constituents of camphorweed, Heterotheca subaxillaris . Phytochemistry . 23 . 4 . 933–934 . 10.1016/S0031-9422(00)85073-6. 1984PChem..23..933L .