Gamochaeta argyrinea
(c) Alison Northup, some rights reserved (CC BY), uploaded by Alison Northup · licence
Family: Asteraceae · Type: Herb · Not Native
Gamochaeta argyrinea is a non-native California herb in the Asteraceae family, recognized by occurs only in ScV with no sympatric species.
Gamochaeta argyrinea is a naturalized annual found in the Lake Oroville area of Butte County in disturbed freshwater marsh at elevations of 40 to 260 meters. Flowering in May, this plant produces flowers with purple to yellow-brown corollas in dense head clusters 1.5 to 5 centimeters long. Growing with decumbent-ascending stems 10 to 24 centimeters tall that are densely white-felty-tomentose, it has a fibrous root system. Its leaves range from 1.5 to 5 centimeters long, oblanceolate to oblanceolate-obovate, with contrasting surfaces—sparsely cobwebby-tomentose on top and white-felty-tomentose underneath. The fruit is tiny, measuring 0.5 to 0.6 millimeters long.
Identification and appearance
Key characters: Geographically isolated; occurs only in ScV with no sympatric species
Habitat and range
Habitat: On fine or gravelly, dry or damp, sometimes granite soil below high water line in disturbed freshwater marsh in destroyed foothill woodland
Elevation: 40-260 m
Outside California: southeastern United States
Bloom period
Gamochaeta argyrinea blooms May.
How to tell it apart
vs Pseudognaphalium: Gamochaeta has tight spike-like flower clusters; Pseudognaphalium has open, branched clusters spreading at the stem tips.; vs Gnaphalium: Gamochaeta forms erect spikes of densely clustered heads; Gnaphalium has prostrate stems with looser, sessile flower clusters.; vs Logfia: Gamochaeta has visible flower heads in narrow spikes; Logfia has heads completely hidden within dense woolly leaf clusters.; vs Stachys: Gamochaeta has spike-like clusters of papery flower heads; Stachys has whorls of tubular lipped mint flowers on square stems.; vs Corethrogyne: Gamochaeta has tiny woolly heads in tight spikes without ray petals; Corethrogyne has obvious white or purple ray petals around each head.
Frequently asked questions
Is Gamochaeta argyrinea native to California?
No. Gamochaeta argyrinea is not native to California (recorded as not native).
When does Gamochaeta argyrinea bloom?
Gamochaeta argyrinea blooms May.
What plant family does Gamochaeta argyrinea belong to?
Gamochaeta argyrinea is in the Asteraceae family, genus Gamochaeta.
What habitat does Gamochaeta argyrinea grow in?
Gamochaeta argyrinea grows in On fine or gravelly, dry or damp, sometimes granite soil below high water line in disturbed freshwater marsh in destroyed foothill woodland.
Related species
Other California species in the same genus, family, or bioregion.
Sources: Jepson eFlora · CalPhotos
Last updated 2026-10-07
Data from The California Species Project — 14,000+ California species with verified data from CNPS, CDFW, USFWS, Cal-IPC, and more.