Perennials, 5-10 cm. Leaves: basal 2-pinnate, 3-20 cm, lobes 2-50 × 0.5-2(-3) mm; cauline 0-12. Heads 1-60 per stem. Peduncles 1-16 cm. Phyllaries whitish to yellowish, 3-14 × 2-5 mm. Ray florets 0. Disc florets 10-80; cor-ollas usually yellowish, sometimes whitish, 2.2-7 mm, tubes 1-2.5 mm, throats campanulate, 1-3 mm, lengths 2-8 times lobes. Cypselae 3-7 mm, ± hirtellous to villous; pappi of 12-22 scales 0.1-3 mm.
Some plants are morphologically intermediate between some pairs of varieties of Hymenopappus filifolius as treated by B. L. Turner (1956).
Duration: Perennial
Nativity: Native
Lifeform: Subshrub
General: Perennial herbs to low subshrubs, to 100 cm tall, from a branching woody caudex; stems usually several per caudex, erect, usually densely whitish tomentose near the base.
Leaves: Mostly basal, arising directly from the woody caudex, with up to 12 smaller leaves alternate on the stems; blades 3-20 cm long, once or twice pinnately dissected, the lobes linear, threadlike, minutely gland-dotted; leaves often whitish tomentose, especially near the leaf base and along center rib.
Flowers: Flower heads discoid, yellow, on slender peduncles and usually arranged in corymbiform arrays at the tips of long scapes; involucres turbinate to campanulate, 4-12 mm high, the bracts (phyllaries) oblanceolate, 2-5 mm wide, usually somewhat hairy, green with membranous tips that can be tinged with yellow, white, or pink; florets all discs, 10-80 per flower head, yellow.
Fruits: Achenes 4 angled, 3-7 mm long, densely short-hairy; topped with a pappus of 12-22 linear-oblong scales.
Ecology: Found on limestone substrates from 3,000-10,000 ft (914-3048 m).
Distribution: Alberta and Saskatchewan, south to WA, CA, and TX
Notes: The mostly basal, pinnately lobed leaves; densely tomentose herbage; and yellow, curling corollas of the discoid heads help identify this species. Though younger plants may occasionally have a single flowering stem arising from a small caudex, this plant normally has several stems arising from a branched caudex and is undisputedly perennial. H. frondosus, though appearing similar, is a taprooted biennial with a single stout stem per plant, which may branch aboveground. H. frondosus also has more stem leaves (10 or more) while H. filifolius has 12 or fewer leaves per stem.
Ethnobotany: A poultice of the root was applied to ease swellings, and a decoction of the root was taken as an emetic. The root was also used as a chewing gum, and the leaves were boiled and baked into bread.
Etymology: Hymenopappus comes from Greek hymen for membrane and pappos for pappus, for the chafflike pappus scales; filifolius means thread like leaves.
Synonyms: None
Editor: LCrumbacher 2011, AHazelton 2017
