Nestotus

R. P. Roberts

Sida 21: 1650. 2005

Common names: Goldenweed mock goldenweed
Etymology: anagram of generic name Stenotus, wherein these species have previously resided
Treatment appears in FNA Volume 20. Treatment on page 169. Mentioned on page 8, 170.
Subshrubs (mat-forming), 2–12 cm; caudices woody, branched. Stems (5–20+) prostrate to erect (bark becoming dark brown to gray, flaky to fibrous when older; twigs, mostly ascending, whitish tan to purplish, mostly 1–4 cm), usually hairy, often stipitate-glandular. Leaves cauline; alternate; sessile; blades (often marcescent, crowded, appearing fasciculate, ascending to spreading) usually 1-nerved, linear to narrowly spatulate (bases ± clasping, often whitish), margins entire, scabrous (cilia spreading-ascendant, short; apices acute to obtuse, often minutely mucronate), faces glabrous or scabrous to villous, often stipitate-glandular. Heads radiate, borne singly. Peduncles 1–5 cm, usually hairy, often stipitate-glandular. Involucres campanulate to hemispheric, (5–10 ×) 7–15 mm. Phyllaries 10–18 in 2(–3) series, 1-nerved (rarely weakly 3- nerved; sometimes weakly keeled), outer linear or narrowly oblong to oblanceolate, inner narrowly oblanceolate, subequal, chartaceous proximally, herbaceous and pliable distally, margins scarious, abaxial faces sometimes sparsely hairy, stipitate-glandular. Receptacles convex, pitted, epaleate. Ray florets 5–11, pistillate, fertile; corollas yellow (laminae elliptic to oblong, 4.5–12 × 1.3–5.5 mm). Disc florets 9–27, bisexual, fertile; corollas yellow, tubes shorter than narrowly or broadly vase-shaped throats, lobes 5, erect to ascending, triangular to narrowly lanceolate; style-branch appendages triangular to narrowly lanceolate. Cypselae (tan to reddish brown) turbinate, slightly compressed, 8–10 ribbed, hairy; pappi persistent, of 30–50 whitish, barbellate, apically attenuate bristles in 1 series. x = 9.

Distribution

nw North America.

Discussion

Species 2 (2 in the flora).

Phylogenetic studies (R. P. Roberts 2002; Roberts and L. E. Urbatsch 2003, 2004; Roberts et al. 2005) have indicated that the two species of Nestotus deserve taxonomic recognition as a distinct genus.

References

None.

Lower Taxa

Key

1 Leaf faces glabrous, margins sometimes ciliate, eglandular; Yukon River drainage, YukonTerritory Nestotus macleanii
1 Leaf faces scabrous, stipitate-glandular, and sparsely villous, margins ciliate, often stipitate-glandular; nw United States Nestotus stenophyllus