Xanthisma junceum |
|
---|---|
rush bristleweed, rush-like bristleweed |
|
Habit | Subshrubs, 25–100 cm; caudices branched, taproots 2–10+ cm. |
Stems | 3–15+, branched in distal 1/2, slender and wiry, glabrous. |
Leaves | basal often withering by flowering, 20–35 × 6–12 mm, pinnatifid; cauline evenly spaced, blades oblong to linear, scalelike, 4–6 × 1–2 mm (except proximalmost), markedly reduced distally, margins usually entire, faces glabrous. |
Peduncles | minutely glandular, if stipitate, then minutely so; bracts 5–25, imbricate, grading into phyllaries. |
Involucres | hemispheric (narrowed at bases), 0.5–0.8 × 1–1.2 cm. |
Ray florets | 15–25; corollas yellow, tubes 3.5–4 mm, laminae 5–6 × 1.5–2.5 mm. |
Disc florets | 25–40+; corollas 4.8–6.3 mm. |
Phyllaries | in 5–6 series, oblong to linear-oblanceolate, 1.5–6.5 mm, apices acute, tipped by white bristle, faces minutely stipitate-glandular. |
Cypselae | narrowly obovoid to oblanceoloid, 1.5–2.5 mm, nerves 12–18, moderately tawny hairy; pappi tawny, 3.5–6 mm, a few abaxial bristles to 1/3 of longest. |
2n | = 8, 16. |
Xanthisma junceum |
|
Phenology | Flowering summer–fall. |
Habitat | Rocky, dry slopes |
Elevation | 100–1000 m (300–3300 ft) |
Distribution |
CA; Mexico (Baja California, Sonora)
|
Discussion | Xanthisma junceum is reported from Arizona, but no specimen has been seen; as it is coastal in distribution, the report is likely based on a misidentified specimen. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 20, p. 390. |
Parent taxa | Asteraceae > tribe Astereae > Xanthisma > sect. Sideranthus |
Sibling taxa | |
Synonyms | Haplopappus junceus, Machaeranthera juncea |
Name authority | (Greene) D. R. Morgan & R. L. Hartman: Sida 20: 1406. (2003) |
Web links |
|