Annuals, 3-15(-25) cm; taprooted or fibrous-rooted. Stems commonly branched from bases, erect to ascending, tomentose. Leaf blades linear, 0.4-5 cm × 0.5-3 mm. Bracts subtending heads linear, 10-25 × 0.5-1 mm, surpassing glomerules. Heads in spiciform glomerules (along distal 1/3-2/3 of main stems, sometimes appearing loosely spiciform). Involucres 2.5-3.5 mm. Phyllaries brownish, bases woolly, inner narrowly triangular with whitish, acute apices. 2n = 14. Flowering Jul-Oct. Lake and pond margins, streamsides, seeps, moist meadows; 1400-3000 m; Ariz., Colo., N.Mex., S.Dak., Utah, Wyo.; Mexico (Chihuahua). Gnaphalium exilifolium, a New World native, differs from the Old World G. uliginosum chiefly in its linear, slightly longer cauline leaves and bracts and in its spiciform arrangement of heads. Pistillate corollas of G. exilifolium are sometimes red-tipped. Cypselae of both taxa are variably smooth to papillate; local populations apparently are consistent in this feature; the variation is otherwise geographically inconsistent.
General: Annual, 3-25 cm tall; stems erect to ascending, simple or branching from the base; herbage densely white tomentose, more so at inflorescence; taprooted or fibrous-rooted. Leaves: Mostly cauline, alternate, linear to linear-oblanceolate, 0.4-5 cm long, 0.5-3 mm wide, grayish tomentose, margins entire; sessile. Flowers: Heads solitary, rarely few, borne on long peduncles, these mostly 4-25 cm long; disk 1.5-3.5 cm wide; phyllaries lance-linear to broadly lanceolate, 7-12 mm long, minutely hispid to villous; ray flowers 5-14, sometimes absent, mostly 1-2.5 cm long, yellow; disk flowers 30-100, 0.8-1 mm long, the base yellowish, apex purplish; flowers June-October. Fruits: Achene, oblong, about 0.5 mm long, glabrous, minutely papillose. Ecology: Moist meadows, streambanks, pond margins, lakeshores, seeps, and seasonally moist open areas; 1400-2900 m (4500-9500 ft); Apache, Coconino, Graham, Navajo, Pima, and Yavapai counties; southwestern U.S., Mexico. Notes: Logfia filaginoides (California cottonrose) [= Filago californica], a similar species from lower elevations rarely encountered in ponderosa pine forests, is an annual, 1-30 cm tall; stems are mostly solitary, branched, grayish to greenish and cobwebby to silky pubescent; leaves are cauline, alternate, linear-oblong to oblanceolate, 0.5-2 cm long, 1-3 mm wide, those subtending the heads 1-2 times the heights of the heads; heads are in clusters of 2-4, with disk flowers only, these reddish to purplish; pappus is of numerous bristles, falling in complete rings. It typically occurs in desert habitats, along slopes, often in dry, sandy or rocky sites at 150-2100 m (500-7000 ft). Slender cudweed is often observed in the first flush of vegetation following burning. Editor: Springer et al. 2008