An erect strict slender perennial herb, to c. 25 cm. tall from a small woody rootstock; roots 3-many, thong-like, each swelling close to the rootstock into a subfusiform root-tuber, or tubers subsessile, tubers up to c. 3 x 1 cm. Stems annual, 1-several, ?simple, leafy, strongly ribbed or angular, glabrous but tomentellous towards the apex. Leaves ascending, regularly spaced on the stem, 2–4.5 cm. long, filiform to narrowly linear, apex acute, margins entire and revolute, lamina glabrous on both surfaces or sparsely puberulous beneath, gland-dotted beneath. Capitula solitary and terminal. Involucre 8–12 x 7–15 mm., broadly campanulate. Phyllaries appendaged; the outer phyllaries from c. 5 mm. long (including appendage), linear; the middle phyllaries to c. 9 x 2.5 mm., including a short oblong appendage narrower than the phyllary base; the inner phyllaries to c. 10 x 1.5 mm., linear with a reduced appendage; appendages puberulous, glandular. Corolla purple, to c. 13 mm. long, with a long slender tube and a short cylindrical exserted limb. Achenes up to c. 3 mm. long, narrowly turbinate-cylindric, c. 10-ribbed, truncate below with a thin flat carpopodium, densely hispidulous and glandular; pappus many-seriate, copious, setae pale-brownish, flattened, barbellate on the margins, increasing to c. 8 mm. long inside.
