Gamochaeta purpurea
Gamochaeta argyrinea
purple everlasting-cudweed, spoon-leaf cudweed, spoon-leaf purple everlasting
silver cudweed, silvery cudweed, silvery everlasting
erect to decumbent-ascending, densely but loosely pannose or pannose-tomentose.
decumbent-ascending, closely white-pannose (hairs usually individually evident, seldom forming clothlike induments).
basal and cauline, basal and proximal cauline usually withering before flowering;
blades oblanceolate to spatulate, 1–6 cm × 5–14 mm (distal similar, at least among proximal heads, margins sometimes sinuate), faces usually bicolor, abaxial closely white-pannose, adaxial usually sparsely arachnose (basal cells of hairs persistent, expanded, glassy), sometimes glabrescent.
basal and cauline, basal present through flowering, blades oblanceolate to oblanceolate-oblong or oblanceolate-obovate, 1.5–5(–8) cm × 5–12(–18) mm (gradually smaller distally), faces bicolor, abaxial closely white-pannose, adaxial sparsely arachnose (evident at 10x).
turbinate-cylindric, 4–4.5 mm, bases sparsely arachnose.
campanulate, 3–3.5 mm, bases sparsely arachnose.
bisexual 3–4; all corollas usually purplish distally.
bisexual 4–5(–6); all corollas purple- to yellow-brown distally.
in 4–5 series, outer ovate-triangular, lengths 1/3–2/3 inner, apices acute-acuminate, inner triangular-lanceolate (usually striate), laminae purplish (in bud) to whitish or silvery (in fruit), apices acute (not apiculate).
in 4–6 series, outer (tawny-transparent, never dark brown) ovate to ovate-lanceolate, lengths 1/3–4/5 inner, apices acute to acuminate, inner elliptic-oblong to oblong, laminae often purplish tinged (around stereome/lamina junction, otherwise hyaline and slightly brownish), apices truncate-rounded, apiculate (flexing slightly outward in fruit).
initially in continuous spiciform arrays 1–4(–5) cm × (5–)10–15 mm, later interrupted (glomerules widely separated, bracteate, the proximal often on relatively long peduncles).
initially in continuous, cylindric arrays 1.5–5 cm × 10–12 mm (pressed), later sometimes interrupted, 5–18 cm × 10–12 mm (pressed; producing axillary glomerules from proximal nodes).
(tan) 0.6–0.7 mm.
(tan) 0.5–0.6 mm.
= 14, 28.
Gamochaeta purpurea
Gamochaeta argyrinea
Gamochaeta purpurea apparently is native to North America and adventive elsewhere.
Basal cells of hairs on adaxial faces of leaves are expanded and glassy (versus hairs filiform to bases in most other species) and are diagnostic for Gamochaeta purpurea. From Maryland northward, plants of G. purpurea produce relatively small basal rosettes and relatively shallow fibrous roots or a filiform taproot; southward and southwestward, the basal rosettes often are larger and the fibrous roots are denser.
Gamochaeta purpurea apparently occurs widely through the world as a weed; it is fairly clearly native to eastern North America, where it is the least weedy of the gamochaetas. Plants of G. purpurea in southern Arizona along perennial streams at the base of the Santa Catalina Mountains were first collected in 1903 (G. L. Nesom 2004) and were, perhaps, accidentally established through visitation; the same sites are heavily infested by other, more aggressive, nonnative species. Collections of G. purpurea also have been made at higher elevations in the Santa Catalina, Rincon, and Chiricahua mountains, where the species is less likely to have been introduced by human activity. It also seems unlikely that plants in scattered Mexican localities were introduced there by human activity.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
Gamochaeta argyrinea has been confused with G. purpurea, which also occurs across the coastal states of eastern United States (G. L. Nesom 2004).
(Discussion copyrighted by Flora of North America; reprinted with permission.)
- Local floras:
OR - Local Web sites:
Flora NW, 
Go Botany, 
IL Wildflowers, 
KS Wildflowers, 
LA Plants, 
MD Biodiversity, 
MI Flora, 
MO Plants, 
PNW Herbaria 
WildflowerSearch
iNaturalist (observations)
USDA Plants Database- LBJ Wildflower Center
- SEINet
- Plants of the World Online
- Encyclopedia of Life
- Wikipedia
- Google Image Search
CA
