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Vascular Plants of California
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Chorizanthe rigida


Higher Taxonomy
Family: PolygonaceaeView DescriptionDichotomous Key
Habit: Annual to shrub [tree]. Stem: nodes swollen or not. Leaf: simple, basal or cauline, generally alternate; ocreae present or 0, generally scarious, persistent or not. Inflorescence: flower clusters in axillary to terminal cyme-, panicle-, raceme-, spike-, umbel- or head-like arrangements, entire inflorescence or main inflorescence branches generally subtended by bracts ("inflorescence bracts"); peduncles present or 0; flower clusters in Eriogoneae-Eriogonoideae subtended by involucre of >= 1 free or +- fused, sometimes awn-tipped bracts ("involucre bracts") or, in Polygonoideae and rarely in Eriogonoideae, not (if bracts completely fused, involucre "tubular"); pedicels in Eriogoneae each often subtended by 2 free, transparent, linear bractlets or in Polygonoideae all subtended by 2+ fused, membranous, wide bractlets. Flower: generally bisexual, small, 1--200 per node; perianth parts 2--6, generally in 2 whorls, free or basally fused, generally petal-like, often +- concave adaxially, often darker at midvein, often turning +- red or +- brown in age; stamens [1]3 or 6--9 in 2 whorls; ovary superior, 1-chambered, ovule 1, styles 1--3. Fruit: achenes, included in or exserted from perianth, generally 3-angled, ovoid or elliptic, generally glabrous.
Genera In Family: 48 genera, +- 1200 species: worldwide, especially northern temperate; some cultivated for food (Coccoloba, sea-grape; Fagopyrum, Rheum, Rumex) or ornamental (Antigonon, lovechain; Coccoloba; Muehlenbeckia; Persicaria; Polygonum), a few timbered (Coccoloba; Triplaris). Several (Emex; Fallopia; Persicaria; Polygonum; Rumex) are weeds. Note: Treatment of genera in Eriogonoideae based on monographic work of James L. Reveal. Involucre number throughout is number (1--many) per ultimate grouping, at tips of ultimate branches; flower number is per flower cluster or involucre, unless otherwise stated. Fagopyrum esculentum Moench not naturalized, considered an historical waif (or garden weed +- presently), therefore not treated.
eFlora Treatment Author: Mihai Costea, except as noted
Scientific Editor: Thomas J. Rosatti, Bruce G. Baldwin.
Genus: ChorizantheView DescriptionDichotomous Key

Habit: Annual [perennial herb], generally hairy. Stem: branches basal or from erect stem, prostrate or decumbent to ascending. Leaf: all basal or basal and cauline, alternate except for bracts, awnless; ocreae 0. Inflorescence: cyme-like, open to +- congested; axes generally 3 from plant base or proximalmost branching node of erect stem, equally or unequally forked; bracts opposite or whorled, entire, generally in whorl of 3 at proximalmost branching node, not distinguishable from basal leaves in plants branched from base, distal generally opposite, proximal leaf-like or some or all scale-like to linear, needle-like, awnless or distal often all awned; involucres sessile, generally solitary at axis forks, distally in loose to dense clusters; involucre tubular, 3--6-ribbed, lobes 3, 5, or 6, equally or unequally awned, awns straight or hooked; involucres at forks often differing from those in clusters. Flower: 1(2) per involucre; pedicel short, included in involucre; perianth glabrous or hairy, white, yellow, pink, maroon, or purple, sometimes 2-colored, lobes (5)6, entire, minutely toothed, or fringed, tip acute, rounded, notched, or 2-lobed; stamens generally 3, 6, or 9. Fruit: generally brown or black, generally ellipsoid, glabrous; embryo straight or curved.
Etymology: (Greek: divided flower, for perianth lobes) Note: Involucre length measurements include lobes and awns unless otherwise specified. Chorizanthe minutiflora and C. aphanantha newly described, added; C. eastwoodiae segregated from C. angustifolia.
eFlora Treatment Author: James L. Reveal, Thomas J. Rosatti, David Gowen & David J. Keil
Reference: Morgan et al. 2014 Phytoneuron 2014-63:1--9; Nelson et al. 2018 Madroño 65:184--191; Gowen & Johnson 2020 Phytotaxa 455(1):1--8.
Chorizanthe rigida (Torr.) Torr. & A. Gray
Habit: Plant compact, stiffly erect, 0.2--0.8(1.5) dm, hairy. Stem: branches generally 0. Leaf: basal and cauline; blades 0.5--2.5 cm, (0.3)0.5--2 cm wide, proximal ovate to widely elliptic, distal linear to linear-lanceolate, awned, hardened into spines in age. Inflorescence: axis 1, generally not forked; bracts opposite, awns 2--4 mm, straight; clusters in leaf axils, short, dense, headlike; involucre 2--3 mm, 3-angled, 3-ribbed, not markedly transversely ridged, lobes 3, lanceolate, thickened, flat, maturing as rigid spines, abaxial lobe 5--10 mm, others 2--5 mm, margins not scarious, awns straight, 0.5--2.5 mm. Flower: 1--2; perianth 1.5--1.8 mm, densely hairy, yellow, inner and outer lobes similar, oblong, entire; stamens 9, fused to perianth tube top. Fruit: (1.5)1.8--2.2 mm. Chromosomes: n=19,20.
Ecology: Common. Sand or gravel; Elevation: 60--1900 m. Bioregional Distribution: SNE, D; Distribution Outside California: to southwestern Utah, western Arizona, northwestern Mexico. Flowering Time: Feb--Jun
Synonyms: Acanthogonum rigidum Torr.
Jepson eFlora Author: James L. Reveal, Thomas J. Rosatti, David Gowen & David J. Keil
Reference: Morgan et al. 2014 Phytoneuron 2014-63:1--9; Nelson et al. 2018 Madroño 65:184--191; Gowen & Johnson 2020 Phytotaxa 455(1):1--8.
Index of California Plant Names (ICPN; linked via the Jepson Online Interchange)

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Citation for this treatment: James L. Reveal, Thomas J. Rosatti, David Gowen & David J. Keil 2022, Chorizanthe rigida, in Jepson Flora Project (eds.) Jepson eFlora, Revision 10,, accessed on July 23, 2024.

Citation for the whole project: Jepson Flora Project (eds.) 2024, Jepson eFlora,, accessed on July 23, 2024.

Chorizanthe rigida
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©2007 California Academy of Sciences
Chorizanthe rigida
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©2004 James M. Andre
Chorizanthe rigida
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©2016 Steve Matson
Chorizanthe rigida
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©2005 Steve Matson
Chorizanthe rigida
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©2015 Keir Morse

More photos of Chorizanthe rigida
in CalPhotos

Geographic subdivisions for Chorizanthe rigida:
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2. County and Jepson Region polygons can be turned off and on using the check boxes.
map of distribution 1

(Note: any qualifiers in the taxon distribution description, such as 'northern', 'southern', 'adjacent' etc., are not reflected in the map above, and in some cases indication of a taxon in a subdivision is based on a single collection or author-verified occurrence).


Data provided by the participants of the  Consortium of California Herbaria.

View all CCH records
All markers link to CCH specimen records. The original determination is shown in the popup window.
Blue markers indicate specimens that map to one of the expected Jepson geographic subdivisions (see left map). Purple markers indicate specimens collected from a garden, greenhouse, or other non-wild location.
Yellow markers indicate records that may provide evidence for eFlora range revision or may have georeferencing or identification issues.

CCH collections by month Flowering-Fruiting Monthly Counts

Duplicates counted once; synonyms included.
Species do not include records of infraspecific taxa, if there are more than 1 infraspecific taxon in CA.
Blue line denotes eFlora flowering time (fruiting time in some monocot genera).