Pittonia 3: 266. 1898.
Perennials, 14–40+ cm. Caudices often highly branched, branches not notably thickened distally. Stems 1–50, erect, sometimes branched near bases, sometimes densely woolly among proximal leaves. Leaves all basal-proximal (new leaves not tightly clustered); blades spatulate to oblanceolate to linear-oblanceolate or linear, entire or with 2 teeth or lobes, sparsely to densely hairy, ± glanddotted. Heads 1–50 per plant, borne singly or in fastigiate arrays. Peduncles 12–40 cm, ± hairy. Involucres 5–10 × 7–12 mm. Outer phyllaries 8–16, 3.8–6.6 mm, margins 0–0.2 (–0.4) mm wide, sometimes to often slightly scarious, abaxial faces ± hairy. Ray-florets 12–26; corollas 7.4–22 mm. Disc-florets 25–180+; corollas yellow, 2.5–3.5 mm. Cypselae 2–3 mm; pappi of 5–7 obovate to oblanceolate, aristate scales 1.6–2.3 mm.
Colo., Kans., N.Mex., Nebr., Okla., Tex., Mexico
Varieties 2 (2 in the flora).
The name “Hymenoxys scaposa (de Candolle) K. F. Parker var. glabra (Nuttall) K. F. Parker” appears never to have been published. Parker did make the combination Hymenoxys acaulis (Pursh) K. F. Parker var. glabra (A. Gray) K. F. Parker based on Actinella scaposa (de Candolle) Nuttall var. glabra A. Gray, which she mistakenly called Actinea scaposa Nuttall var. glabra A. Gray.
|1||Stems not densely woolly among proximal leaves; leaves crowded (internodes not evident); Colorado, Kansas, Nebraska, New Mexico, Oklahoma, Texas||Tetraneuris scaposa var. scaposa|
|1||Stems densely woolly among proximal leaves; leaves not crowded (internodes evident); Texas||Tetraneuris scaposa var. argyrocaulon|