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

riverside spineflower, Xantus' spineflower

Santa Barbara spineflower, Wheeler's spineflower

Habit Plants erect to infrequently spreading, (0.3–)0.5–2.5(–3) × 0.5–3(–5) dm, thinly pubescent. Plants erect to spreading, 0.5–2(–2.5) × 1–2 dm, thinly pubescent.
Leaves

basal or nearly so;

petiole 1–2(–3) cm;

blade oblong or oblong-ovate to ovate, 0.3–1(–1.5) × 0.3–0.8(–1) cm, thinly pubescent adaxially, densely tomentose abaxially.

basal;

petiole 0.5–3 cm;

blade elliptic to oblong, 0.5–2 × 0.2–0.6 cm, thinly pubescent adaxially, tomentose abaxially.

Inflorescences

mostly flat-topped and openly branched, usually reddish;

bracts persistent, 2, usually leaflike at proximal nodes and similar to proximal leaf blades only more reduced, short-petiolate, oblong-ovate to ovate, 0.3–0.8 cm × 2–6 mm, becoming sessile, reduced and scalelike at distal nodes, linear, acicular, often acerose, 0.1–0.4 cm × 0.5–1 mm, awns straight, 0.5–1 mm.

mostly flat-topped, openly branched, greenish to reddish;

bracts persistent, 2, usually leaflike at proximal nodes and similar to leaf blades, short-petiolate, oblong, 0.5–1.2 cm × 2–4 mm, sessile, reduced and scalelike at distal nodes, linear, acicular, often acerose, 0.1–0.5 cm × 0.5–1 mm, awns straight, 0.5–1 mm.

Involucres

in open clusters with 1 at node of dichotomies, reddish, cylindric, not ventricose, 3–4.5 mm, not corrugate, without scarious or membranous margins, thinly to densely pubescent;

teeth spreading, unequal, 0.7–1.5 mm, 3 longer ones more erect than 3 shorter and less-prominent ones;

awns uncinate, 0.5–1 mm.

in dense terminal clusters with 1 at node of dichotomies, reddish, cylindric, not ventricose, 2–2.5 mm, corrugate, without scarious or membranous margins, thinly pubescent with stoutish, recurved hairs;

teeth spreading, unequal, 0.3–0.8(–1) mm, with 3 longer ones more erect than 3 shorter and less-prominent ones;

awns uncinate, 0.3–0.5 mm.

Flowers

long-exserted;

perianth rose to red, infrequently with white lobes, cylindric, 4.5–6 mm, pubescent;

tepals connate ca. 2/3 their length, monomorphic to slightly dimorphic, narrowly oblanceolate, rounded apically, those of outer whorl occasionally slightly broader and longer than those of inner whorl;

stamens 9, mostly included;

filaments distinct, 4–6 mm, glabrous;

anthers pink to red, oblong, 0.5–0.6 mm.

exserted;

perianth white or rose or red with white lobes, cylindric, 2.5–3 mm, glabrous except for few scattered hairs ca. midlength along midrib abaxially;

tepals connate 1/2 their length, monomorphic to slightly dimorphic, oblong, rounded apically, those of outer whorl usually slightly broader and longer than those of inner whorl;

stamens 6, included;

filaments distinct, 1.5–2 mm, glabrous;

anthers pink to red, oblong, 0.3–0.4 mm.

Achenes

brown, lenticular, 4–4.5 mm.

brown, lenticular, 2.5–3 mm.

Chorizanthe xanti

Chorizanthe wheeleri

Phenology Flowering Apr–Jun.
Habitat Gravelly to rocky slopes, coastal scrub communities
Elevation 0-400(-600) m (0-1300(-2000) ft)
Distribution
from FNA
CA
[WildflowerSearch map]
[BONAP county map]
from FNA
CA
[WildflowerSearch map]
[BONAP county map]
Discussion

Varieties 2 (2 in the flora).

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

Chorizanthe wheeleri is a rare insular endemic known only from Santa Cruz and Santa Rosa islands.

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

Key
1. Involucres thinly pubescent
var. xanti
1. Involucres densely white-pubescent
var. leucotheca
Source FNA vol. 5, p. 463. FNA vol. 5, p. 464.
Parent taxa Polygonaceae > subfam. Eriogonoideae > Chorizanthe > subg. Amphietes > sect. Ptelosepala Polygonaceae > subfam. Eriogonoideae > Chorizanthe > subg. Amphietes > sect. Ptelosepala
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. watsonii, C. wheeleri
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. watsonii, C. xanti
Subordinate taxa
C. xanti var. leucotheca, C. xanti var. xanti
Synonyms C. insularis
Name authority S. Watson: Proc. Amer. Acad. Arts 12: 272. (1877) S. Watson: Proc. Amer. Acad. Arts 12: 272. (1877)
Web links