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striped cottonthorn, striped horsebrush

catclaw horsebrush, cotton-thorn horsebrush, shortspine horsebrush, spiny horsebrush

Habit Shrubs, 50–200 cm. Shrubs, 10–100 cm.
Stems

1–5+, erect, spiny, unevenly pannose with glabrescent streaks.

1–5+, erect or spreading, spiny, evenly pannose.

Leaves

primaries forming ascending spines, 10–30 mm;

secondaries filiform to clavate, 3–20 (× 1+) mm, glabrous or nearly so.

primaries forming recurved spines, 5–25 mm;

secondaries linear-filiform to spatulate, 3–25 (× 1–2) mm, glabrous or glabrescent.

Peduncles

1–4 mm.

5–30 mm.

Involucres

turbinate, ca. 7 mm.

hemispheric, 8–12 mm.

Florets

5;

corollas pale yellow, ca. 9 mm.

5–8;

corollas pale to bright yellow, 6–10 mm.

Phyllaries

5, oval-elliptic.

4–6, oblong to ovate.

Heads

2–5.

1–2 (in axils of spines).

Cypselae

2.5–3.5 mm, glabrous;

pappi of 75–100 bristles ca. 8 mm.

6–8 mm, copiously pilose (hairs 9–12 mm);

pappi of ca. 25, subulate scales 6–9 mm.

2n

= 60.

= 60.

Tetradymia argyraea

Tetradymia spinosa

Phenology Flowering summer. Flowering spring.
Habitat Rocky sites, pinyon-juniper woodlands Usually sandy soils of alkali sinks, shadscale scrub, pinyon-juniper woodlands
Elevation 1400–2100 m (4600–6900 ft) 800–2400 m (2600–7900 ft)
Distribution
from FNA
CA
[WildflowerSearch map]
[BONAP county map]
from FNA
CA; CO; ID; MT; NM; NV; OR; UT; WY
[WildflowerSearch map]
[BONAP county map]
Source FNA vol. 20, p. 631. FNA vol. 20, p. 632.
Parent taxa Asteraceae > tribe Senecioneae > Tetradymia Asteraceae > tribe Senecioneae > Tetradymia
Sibling taxa
T. axillaris, T. canescens, T. comosa, T. filifolia, T. glabrata, T. nuttallii, T. spinosa, T. stenolepis, T. tetrameres
T. argyraea, T. axillaris, T. canescens, T. comosa, T. filifolia, T. glabrata, T. nuttallii, T. stenolepis, T. tetrameres
Name authority Munz & J. C. Roos: Aliso 2: 237. (1950) Hooker & Arnott: Bot. Beechey Voy., 360. (1839)
Web links