Chrysothamnus eremobius |
Chrysothamnus molestus |
|
---|---|---|
pintwater rabbitbrush |
Arizona rabbitbrush |
|
Habit | Subshrubs, 10–30 cm; with woody, highly branched caudices, bark whitish to dark gray, finely ridged, ± fibrous with age. | Shrubs, 8–20 cm; with woody, highly branched caudices, bark dark gray, highly fibrous with age. |
Stems | erect, green becoming whitish, glabrous, ± resinous. |
ascending, green, ± puberulent, stipitate-glandular. |
Leaves | ascending to spreading; petiolate; blades mostly 3-nerved (nerves reticulate, raised), elliptic to oblanceolate or obovate, 20–80 × (7–)10–25 mm (mostly larger basally, ± reduced distally), flat, apices acute, faces glabrous, gland-dotted. |
erect to closely ascending; sessile; blades with ± evident midnerves, linear to narrowly elliptic, 7–20 × 0.7–1.5 mm, sulcate, sometimes apiculate, apices acute, faces moderately puberulent, uniformly stipitate-glandular. |
Involucres | cylindric to turbinate, 6.5–8.8 × 1.8–2.5 mm. |
subcylindric, 9–11 × 2.5–3.5 mm. |
Disc florets | 5(–6); corollas 4–5 mm, lobes 0.8–1.2 mm; style branches 2.2–2.7 mm, appendages 0.8–1.2 mm. |
5; corollas 5.5–7.5 mm, lobes 0.9–1.5 mm; style branches 2.7–3.2 mm, appendages 1–1.7 mm. |
Phyllaries | 19–24(–30) in 3–4 series, in vertical ranks, tan with apical green spot, midnerves evident distally, ovate to lanceolate, 1.5–6 × 0.7–1.5 mm, unequal, chartaceous, apices obtuse to acuminate, flat, faces glabrous. |
± 20 in 4–5 series, in 4–5 strong vertical ranks, tan, often with green or dark subapical splotch, midnerves often obscure, linear or lanceolate to elliptic, 2–9 × 0.5–1.3 mm, unequal, outer ± herbaceous, inner chartaceous, strongly keeled, apices acute to rounded, tip cupped, faces of outer glabrous or puberulent. |
Heads | in condensed, cymiform arrays, not overtopped by leaves. |
in small cymiform to racemiform arrays. |
Cypselae | cylindric, 2.5–3 mm, faces hairy; pappi tan, 3.1–3.9 mm. |
tan, elliptic, 4.2–6 mm, mostly 5-ribbed, faces glabrous, sparsely glandular; pappi tan, 6–7.5 mm. |
2n | = 18. |
= 18. |
Chrysothamnus eremobius |
Chrysothamnus molestus |
|
Phenology | Flowering late summer–fall. | Flowering late summer–fall. |
Habitat | Crevices of limestone cliffs | Rocky soils, mostly on limestone pinyon-juniper woodland |
Elevation | 1400–1700 m (4600–5600 ft) | 1800–2400 m (5900–7900 ft) |
Distribution |
NV |
AZ |
Discussion | Of conservation concern. Chrysothamnus eremobius is known only from the Pintwater and Sheep ranges of southern Nevada. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Chrysothamnus molestus is known only from Coconino County. It is in the Center for Plant Conservation’s National Collection of Endangered Plants. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 20, p. 189. | FNA vol. 20, p. 190. |
Parent taxa | ||
Sibling taxa | ||
Synonyms | C. viscidiflorus var. molestus | |
Name authority | L. C. Anderson: Brittonia 35: 23, fig. 1. (1983) | (S. F. Blake) L. C. Anderson: Madroño 17: 222. (1964) |
Web links |