Tetraneuris acaulis
Pittonia 3: 265. 1898.
Perennials, 2–30+ cm. Caudices ± branched, branches notably thickened distally. Stems 1–35 (–60), erect, unbranched. Leaves all basal, new leaves tightly clustered; blades spatulate or oblanceolate to linear-oblanceolate, entire, glabrous or ± hairy, often lanuginose, sericeous, or strigoso-canescent, eglandular or ± glanddotted. Heads 1–35 (–60) per plant, borne singly. Peduncles 0.5–30 cm, ± hairy. Involucres 7–12 × 8–16 mm. Outer phyllaries 6–12, 3.9–9 (–11.5) mm, margins 0–0.4 mm wide, sometimes slightly scarious, abaxial faces ± hairy. Ray-florets 8–15 (–21); corollas 9–19 mm. Disc-florets 25–200+; corollas yellow, 2.7–4.3 mm. Cypselae 2–4 mm; pappi of 5–8 obovate to oblanceolate, aristate scales 2.2–3.7 mm.
Distribution
Alta., Sask., Ariz., Calif., Colo., Idaho, Kans., Mont., N.Dak., N.Mex., Nebr., Nev., Okla., S.Dak., Tex., Utah, Wyo.
Discussion
Varieties 4 (4 in the flora).
Selected References
None.
Lower Taxa
Key
| 1 | Leaves sparsely to densely hairy, often lanuginose, sometimes sericeous, not strigoso-canescent; peduncles 0.5–8(–12) cm; outer phyllaries 6.8–9(–11.5) mm; growing at (2100–)3000–3900 m | Tetraneuris acaulis var. caespitosa |
| 1 | Leaves sparsely to densely hairy, often strigoso-canescent; peduncles (1–)5–20(–30) cm; outer phyllaries 4–7.5 mm; growing at 700–2900(–3500) m | > 2 |
| 2 | Leaf blades usually densely, sometimes sparsely, strigoso-canescent; e of continental divide (except for 2 reports from nw Idaho) | Tetraneuris acaulis var. acaulis |
| 2 | Leaf blades glabrous or sparsely to moderately to sometimes densely hairy, not strigoso-canescent; w of continental divide | > 3 |
| 3 | Leaf blades glabrous or usually sparsely to moderately or sometimes densely hairy, densely gland-dotted; n Arizona, se California, w Colorado, s Idaho, e Nevada, Utah | Tetraneuris acaulis var. arizonica |
| 3 | Leaf blades glabrous or sparsely to moderately hairy, at least some (usually most or all) eglandular or sparsely gland-dotted; w Colorado, c, ne Utah, and sw Wyoming | Tetraneuris acaulis var. epunctata |