Stenotus

Perennials, 2–30(–60) cm (mat-forming or cespitose [pulvinate]; branched caudices, taproots ± well-developed). Stems erect (usually white, proximally often clothed with marcescent leaves), simple, glabrous or scabrous, villous, or lanate, eglandular, viscid, or stipitate-glandular. Leaves basal or cauline; alternate; petiolate; blades (whitish proximally, green or grayish distally) 1- or 3-nerved (nerves raised abaxially or not), linear to broadly oblanceolate (rigid or pliable), margins entire, sometimes ciliate, eglandular [glandular], faces glabrous, scabrous, or villous to lanate, viscid or stipitate-glandular. Heads radiate [discoid], usually borne singly, sometimes (2–4) in corymbiform arrays. Involucres campanulate to hemispheric, ([6–]9–28 ×) [5–]6–15 mm. Phyllaries 10–37(–64) in 2–4 series, 1- or 3-nerved (sometimes keeled proximally), lanceolate or oblong to broadly oblanceolate, unequal to equal, indurate proximally, chartaceous or herbaceous distally, margins scarious, entire or fimbriate (apices acute to obtuse or rounded), abaxial faces sometimes villous, viscid, and/or stipitate-glandular. Receptacles convex, pitted, epaleate. Ray florets [0] 5–17, pistillate, fertile; corollas yellow. Disc florets 14–45, bisexual, fertile; corollas yellow, tubes shorter than narrowly funnelform to vase-shaped, or ± ampliate throats, lobes 5, erect, triangular; style-branch appendages subulate to lanceolate. Cypselae ± prismatic to oblanceoloid or linear, often flattened, 6–12-nerved, faces usually sericeous, sometimes glabrous; pappi persistent, of 30–75, whitish, fine, barbellate, apically attenuate bristles in 1 series (spreading at maturity). x = 9.

Distribution

w North America, nw Mexico.

Discussion

Species 4 (3 in the flora).

Selected References

Morse, C. A. 1994. Systematics and Taxonomy of Stenotus Nutt. (Asteraceae: Astereae). M.S. thesis. University of Kansas.

Lower Taxa

Stenotus acaulis, Stenotus armerioides, Stenotus lanuginosus

Key

1	Stems and leaves villous to lanate, eglandular or densely stipitate-glandular; leaves pliable; taproots weakly developed	Stenotus lanuginosus
1	Stems and leaves glabrous or scabrous, eglandular, viscid, or stipitate-glandular; leaves rigid; taproots usually well developed	> 2
2	Leaf margins usually roughly scabrous; outer phyllary apices acute, green portions usually longer than broad	Stenotus acaulis
2	Leaf margins sometimes ciliate (often minutely); outer phyllary apices obtuse to rounded, green portions as long as broad	Stenotus armerioides