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devil's spineflower, rigid spineflower, rigid spiny-herb, spiny-herb

wrinkled spineflower

Habit Plants erect, 0.2–0.8(–1.5) × 0.1–0.7(–1) dm, pubescent. Plants erect, 0.3–1.5 × 0.3–1 dm, thinly tomentose.
Leaves

basal and cauline;

petiole 0.5–3(–4) cm;

basal blade broadly elliptic to obovate, 0.5–2.5 × (0.3–)0.5–2 cm, thinly pubescent adaxially, more densely so to tomentose abaxially;

proximal cauline leaf soon deciduous, 1, blade similar to basal leaf blades only 1–2(–2.5) × 0.5–1.5 cm, mucronate to awn-tipped, awn mostly 2–4 mm;

distal cauline leaf blade persistent, 1 per node, sessile, blade linear to linear-lanceolate, 0.1–1.5 × 0.05–0.15 cm, becoming hard and thornlike with age.

basal or nearly so;

petiole 0.5–2(–3) cm;

blade round-ovate, (0.5–)0.8–1.5(–2) × (0.3–)0.5–1.5(–2) cm, thinly floccose to tomentose.

Inflorescences

with involucres in dense clusters in axils of bracts, these on short shoots and each subtended by cauline leaves;

bracts 2, subopposite to opposite, linear, 0.5–1(–1.2) cm × 1–2 mm, awns straight, 2–4 mm.

with involucres in small clusters 0.5–1 cm diam., green to tan or reddish;

bracts 2, linear to linear-lanceolate, acicular, 2–7 cm × 1–2.5 mm, awns slightly curved, 0.5–1 mm.

Involucres

1, greenish, urceolate, 3-ribbed, 2–3 mm, corrugate, pubescent, rarely villous near base in some;

teeth 3, unequal, with thickened anterior tooth toward base, 5–10 mm, sometimes expanding and becoming lanceolate to narrowly elliptic, others 0.5–1.2 mm;

awns straight.

1, green to tan, cylindric, 3-angled but 3-ribbed, 3–4 mm, markedly transverse corrugate, glabrate;

teeth 3, equal, 2–4.5 mm;

awns uncinate, 0.6–1 mm.

Flowers

1–2, included to slightly exserted;

perianth yellow, cylindric, 1.5–1.8 mm, densely pubescent abaxially;

tepals connate ca. 2/3 their length, monomorphic, oblong, rounded, entire apically;

stamens 9, slightly exserted;

filaments distinct, 0.5–1 mm, glabrous;

anthers yellowish, ovate, 0.2–0.3 mm.

1, included to slightly exserted;

perianth white, cylindric, 2–2.5 mm, thinly pubescent abaxially;

tepals connate ca. 2/3 their length, monomorphic, oblong, acute, entire apically;

stamens 6, slightly exserted;

filaments distinct, 0.8–1 mm, glabrous;

anthers cream, ovate, 0.4–0.5 mm.

Achenes

brown, 3-gonous, (1.5–)1.8–2.2 mm.

brown, lenticular, 2.5–3 mm.

2n

= 38, 40.

= 38.

Chorizanthe rigida

Chorizanthe corrugata

Phenology Flowering Feb–Jun. Flowering Feb–May.
Habitat Sandy to gravelly or rocky flats and slopes, desert scrub Sandy to gravelly flats and slopes, mixed grassland, saltbush, creosote bush, and sagebrush communities
Elevation -60-1900 m. (-200-6200 ft.) -70-1000 m (-200-3300 ft)
Distribution
from FNA
AZ; CA; NV; UT; Mexico (Baja California, Sonora)
[WildflowerSearch map]
[BONAP county map]
from FNA
AZ; CA; NV; Mexico (Baja California, Sonora)
[WildflowerSearch map]
[BONAP county map]
Discussion

Anyone with the misfortune to step bare-footed on Chorizanthe rigida after the plant has dried instantly appreciates its common name. The species is widespread on the Mojave and Sonoran deserts but only occasionally is it locally abundant or weedy. It is found also along the Lahontan Trough in western Nevada, a well-known biogeographic extension route north of the Mojave Desert (J. L. Reveal 1980). The exceedingly compact and dense inflorescences with suppressed secondary branches result in a series of leaves and bracts that subtend a closely arranged series of bracteated and involucrated flowers.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Chorizanthe corrugata is found mainly in the Mojave and Sonoran deserts. The narrow, transversely corrugated involucral tube is diagnostic. Some anomalous flowers with four or eight stamens have been seen but this condition was always associated with other flowers bearing the normal number.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Source FNA vol. 5, p. 467. FNA vol. 5, p. 468.
Parent taxa Polygonaceae > subfam. Eriogonoideae > Chorizanthe > subg. Amphietes > sect. Acanthogonum Polygonaceae > subfam. Eriogonoideae > Chorizanthe > subg. Amphietes > sect. Acanthogonum
Sibling taxa
C. angustifolia, C. biloba, C. blakleyi, C. brevicornu, C. breweri, C. clevelandii, C. corrugata, C. cuspidata, C. diffusa, C. douglasii, C. fimbriata, C. howellii, C. leptotheca, C. membranacea, C. obovata, C. orcuttiana, C. palmeri, C. parryi, C. polygonoides, C. procumbens, C. pungens, C. rectispina, C. robusta, C. spinosa, C. staticoides, C. stellulata, C. uniaristata, C. valida, C. ventricosa, C. watsonii, C. wheeleri, C. xanti
C. angustifolia, C. biloba, C. blakleyi, C. brevicornu, C. breweri, C. clevelandii, C. cuspidata, C. diffusa, C. douglasii, C. fimbriata, C. howellii, C. leptotheca, C. membranacea, C. obovata, C. orcuttiana, C. palmeri, C. parryi, C. polygonoides, C. procumbens, C. pungens, C. rectispina, C. rigida, C. robusta, C. spinosa, C. staticoides, C. stellulata, C. uniaristata, C. valida, C. ventricosa, C. watsonii, C. wheeleri, C. xanti
Synonyms Acanthogonum rigidum Acanthogonum corrugatum
Name authority (Torrey) Torrey & A. Gray: Proc. Amer. Acad. Arts 8: 198. (1870) (Torrey) Torrey & A. Gray: Proc. Amer. Acad. Arts 8: 198. (1870)
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