OregonFlora: Pseudognaphalium luteoalbum vs. Pseudognaphalium thermale

	Pseudognaphalium luteoalbum	Pseudognaphalium thermale
	weedy cudweed	northwestern rabbit-tobacco, Wright's cudweed
Habit	Plants annual, 1.5–4 dm.	Plants perennial, 2–9 dm.
Stems	floccose-tomentose, not glandular.	floccose-tomentose, not glandular.
Leaves	1.5–5 cm, broadly or narrowly linear to oblanceolate, bases clasping, not decurrent; surfaces floccose-tomentose, not glandular.	1.5–9 cm, linear to oblanceolate to narrowly oblong, bases decurrent on stem, not clasping; surfaces floccose-tomentose, sometimes minutely glandular beneath longer trichomes.
Involucres	3–4 mm.	4–6 mm.
Phyllaries	in 3–4 series, green or brownish; surfaces glabrous.	in 3–4 series, white; surfaces glabrous.
Fruits	0.3–0.5 mm, brown; pappi white.	0.5–0.6 mm, brown; pappi white.
Outer florets	130–160; corolla tips red.	35–55; corolla tips yellow.
Inner florets	5–10.	4–7.
2n	=14, 16, 28.

	Pseudognaphalium luteoalbum	Pseudognaphalium thermale
Distribution	[WildflowerSearch map]	[WildflowerSearch map]
Discussion	Riverbanks, roadsides, disturbed areas. Flowering May–Aug. 0–300 m. CR, Est, Sisk, WV. CA, NV, WA; southeast to FL, south to Mexico; Africa, Asia, Australia, Europe, Pacific Islands. Exotic.	Conifer forests, shrublands, grasslands, riverbanks, lakesides, dry slopes, roadsides, disturbed areas. Flowering Jun–Oct. 0–2000 m. BW, Casc, CR, ECas, Sisk. CA, ID, NV, WA; north to British Columbia, northeast to Alberta, east to WY, southeast to UT. Native. Pseudognaphalium thermale is here recognized at the species rank rather than its earlier placement as a subspecies of P. canescens or a variety of P. microcephalum.
Source	Flora of Oregon, volume 2, page 327 Kenton Chambers	Flora of Oregon, volume 2, page 327 Kenton Chambers
Sibling taxa	P. californicum, P. macounii, P. stramineum, P. thermale	P. californicum, P. luteoalbum, P. macounii, P. stramineum
Synonyms		Gnaphalium canescens ssp. thermale, Gnaphalium microcephalum, Gnaphalium microcephalum var. thermale, Gnaphalium thermale
Web links	Local floras: BC, CA, OR, WA Local Web sites: CalFlora, CalPhotos, Flora NW, PNW Herbaria WildflowerSearch iNaturalist (observations) USDA Plants Database LBJ Wildflower Center SEINet Plants of the World Online Encyclopedia of Life Wikipedia Google Image Search	Local floras: BC, CA, OR, WA Local Web sites: CalFlora, CalPhotos, Flora NW, PNW Herbaria WildflowerSearch iNaturalist (observations) LBJ Wildflower Center SEINet Plants of the World Online Encyclopedia of Life Wikipedia Google Image Search

Pseudognaphalium thermale

weedy cudweed

northwestern rabbit-tobacco, Wright's cudweed

Habit

Plants annual, 1.5–4 dm.

Plants perennial, 2–9 dm.

Stems

floccose-tomentose, not glandular.

Leaves

1.5–5 cm, broadly or narrowly linear to oblanceolate, bases clasping, not decurrent;

surfaces floccose-tomentose, not glandular.

1.5–9 cm, linear to oblanceolate to narrowly oblong, bases decurrent on stem, not clasping;

surfaces floccose-tomentose, sometimes minutely glandular beneath longer trichomes.

Involucres

3–4 mm.

4–6 mm.

Phyllaries

in 3–4 series, green or brownish;

surfaces glabrous.

in 3–4 series, white;

surfaces glabrous.

Fruits

0.3–0.5 mm, brown;

pappi white.

0.5–0.6 mm, brown;

pappi white.

Outer florets

130–160;

corolla tips red.

35–55;

corolla tips yellow.

Inner florets

5–10.

4–7.

=14, 16, 28.

Pseudognaphalium thermale

Distribution

[WildflowerSearch map]

Discussion

Riverbanks, roadsides, disturbed areas. Flowering May–Aug. 0–300 m. CR, Est, Sisk, WV. CA, NV, WA; southeast to FL, south to Mexico; Africa, Asia, Australia, Europe, Pacific Islands. Exotic.

Conifer forests, shrublands, grasslands, riverbanks, lakesides, dry slopes, roadsides, disturbed areas. Flowering Jun–Oct. 0–2000 m. BW, Casc, CR, ECas, Sisk. CA, ID, NV, WA; north to British Columbia, northeast to Alberta, east to WY, southeast to UT. Native.

Pseudognaphalium thermale is here recognized at the species rank rather than its earlier placement as a subspecies of P. canescens or a variety of P. microcephalum.

Source

Flora of Oregon, volume 2, page 327
Kenton Chambers

Sibling taxa

P. californicum, P. macounii, P. stramineum, P. thermale

P. californicum, P. luteoalbum, P. macounii, P. stramineum

Synonyms

Gnaphalium canescens ssp. thermale, Gnaphalium microcephalum, Gnaphalium microcephalum var. thermale, Gnaphalium thermale

Web links