The green links below add additional plants to the comparison table. Blue links lead to other Web sites.
enable glossary links

five-tooth spineflower, Watson's spineflower

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

Habit Plants spreading to erect, 0.2–1(–1.5) × 0.2–1(–1.5) dm, densely canescent-strigose. Plants erect, 0.2–0.8(–1.5) × 0.1–0.7(–1) dm, pubescent.
Leaves

basal or nearly so;

petiole (0.5–)1–2.5(–3) cm;

blade oblanceolate, (0.3–)0.5–1.5(–2) × 0.2–0.4(–0.5) cm, thinly floccose to sparsely tomentose.

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.

Inflorescences

with involucres in small clusters 0.5–1 cm diam., greenish to reddish;

bracts 2, with laminar ones oblanceolate, (0.5–)0.8–1.5(–2) cm × (1–)2–4 mm, those at distal nodes becoming sessile, reduced and scalelike, linear-lanceolate, acicular, awns slightly curved, 0.5–1 mm.

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.

Involucres

1, green, cylindric, 5-ribbed, 3–4.5 mm, finely corrugate, pubescent;

teeth 5, erect, unequal, with leaflike, narrowly lanceolate, 2–6 mm anterior tooth, others linear, 1–2 mm;

awn uncinate, 0.4–0.8(–1) mm.

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.

Flowers

1, included to slightly exserted;

perianth yellow, cylindric, 1.5–2.5 mm, thinly pubescent abaxially;

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

stamens 3 or 9, slightly exserted;

filaments distinct, 0.8–1 mm, glabrous;

anthers yellow, ovate, 0.2–0.3 mm.

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.

Achenes

brown, lenticular, 2.5–3 mm.

brown, 3-gonous, (1.5–)1.8–2.2 mm.

2n

= 38, 40.

Chorizanthe watsonii

Chorizanthe rigida

Phenology Flowering Apr–Aug. Flowering Feb–Jun.
Habitat Sandy to gravelly flats and slopes, mixed grassland, saltbush and sagebrush communities, pinyon-juniper woodlands Sandy to gravelly or rocky flats and slopes, desert scrub
Elevation 300-2400 m (1000-7900 ft) -60-1900 m. (-200-6200 ft.)
Distribution
from FNA
AZ; CA; ID; NV; OR; UT; WA
[WildflowerSearch map]
[BONAP county map]
from FNA
AZ; CA; NV; UT; Mexico (Baja California, Sonora)
[WildflowerSearch map]
[BONAP county map]
Discussion

Chorizanthe watsonii is widely distributed in the cold desert of the Great Basin and in the northern part of the warmer Mojave Desert. Plants in the northern part of the range (especially on the Palouse Prairie of south-eastern Washington) usually have three stamens.

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

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.)

Source FNA vol. 5, p. 468. FNA vol. 5, p. 467.
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. rigida, C. robusta, C. spinosa, C. staticoides, C. stellulata, C. uniaristata, C. valida, C. ventricosa, C. wheeleri, C. xanti
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
Synonyms Acanthogonum rigidum
Name authority Torrey & A. Gray: Proc. Amer. Acad. Arts 8: 199. (1870) (Torrey) Torrey & A. Gray: Proc. Amer. Acad. Arts 8: 198. (1870)
Web links