Chrysothamnus vaseyi |
Chrysothamnus humilis |
|
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Vasey's rabbitbrush |
Truckee green rabbitbrush, Truckee rabbitbrush |
|
Habit | Shrubs, 10–30 cm; caudices woody, very branched, bark tan to dark gray, fibrous with age. | Shrubs, 10–30 cm; with woody, branched caudices, bark becoming dark gray, fibrous with age. |
Stems | ascending, green becoming tan, glabrous or puberulent, resin-dotted to resinous. |
ascending, green, sparsely to densely puberulent, sparsely glandular. |
Leaves | ascending to spreading; sessile; blades with faint midnerves, linear to oblanceolate, 10–40 × 1–2.5 mm, flat or sulcate, usually not twisted, margins eciliate or sparsely puberulent, apices acute to apiculate, faces usually glabrous, sometimes puberulent, usually gland-dotted, resinous. |
ascending to spreading; sessile; blades with faint midnerves and pair of collaterals, narrowly elliptic to oblanceolate, 10–30 × 0.7–1.2 mm, flat to sulcate, apices acute (often apiculate), faces moderately puberulent, sparsely stipitate-glandular. |
Involucres | cylindric to obconic, (5–)6–8 × 2–4 mm. |
turbinate, 6–10 × 3–4 mm. |
Disc florets | 5–7; corollas 4.5–6.5 mm, lobes 1.2–1.7 mm; style branches 2.5–3.8 mm, appendages 0.8–1.2 mm. |
2–3(–4); corollas 5.5–8 mm, lobes 1–1.7 mm; style branches 2–2.7(–3.4) mm (included in or barely surpassing spreading corolla lobes), appendages 0.8–1.4 mm (lengths about equaling stigmatic portion). |
Phyllaries | 12–18 in 3–4 series, in weak vertical ranks, mostly tan, greenish apically, midnerves evident and ± expanded distally, ovate to elliptic, unequal, 1.5–7 × 1–1.8 mm, chartaceous, weakly keeled, margins scarious, ciliate to lacerate, apices acute to obtuse-rounded, faces glabrous or gland-dotted. |
(12–)14–18 in 3–4 series, ± in vertical ranks, mostly tan, sometimes green-tipped, ovate or oblong to elliptic, unequal, 2.5–7.5 × 1–1.8 mm, chartaceous, outer ± herbaceous wholly or distally, weakly keeled, midveins faint, apices acute to obtuse, faces sparsely puberulent. |
Heads | in dense cymiform arrays (to 5 cm wide), sometimes overtopped by distal leaves. |
in densely cymiform arrays, often overtopped by distal leaves. |
Cypselae | reddish brown, cylindric to turbinate, 4–5 mm, 5–10-nerved, faces glabrous; pappi tan (fine), 3.5–5 mm. |
reddish brown, turbinate, 4–6 mm, densely hairy; pappi tan, 5–7 mm. |
2n | = 18. |
= 18. |
Chrysothamnus vaseyi |
Chrysothamnus humilis |
|
Phenology | Flowering summer–fall. | Flowering summer–fall. |
Habitat | Open woods (oak or ponderosa pine) and dry meadows | Sagebrush grasslands, open slopes in deserts, tolerant of alkali |
Elevation | 1700–2900 m (5600–9500 ft) | 1400–3100 m (4600–10200 ft) |
Distribution |
CO; NM; NV; UT; WY |
CA; ID; NV; OR; WA
|
Source | FNA vol. 20, p. 191. | FNA vol. 20, p. 189. |
Parent taxa | ||
Sibling taxa | ||
Synonyms | Bigelowia vaseyi | C. viscidiflorus subsp. humilis |
Name authority | (A. Gray) Greene: Erythea 3: 96. (1895) | Greene: Pittonia 3: 24. (1896) |
Web links |