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Vascular Plants of California
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Centrostegia thurberi


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: CentrostegiaView Description 

Etymology: (Greek: spurred roof, for basal awns of involucre)
eFlora Treatment Author: James L. Reveal & Thomas J. Rosatti
Centrostegia thurberi A. Gray
Habit: Annual, erect, 0.3--2(3) dm, sparsely glandular. Leaf: basal; blades (0.5)1--3.5(4) cm, 0.3--0.8(1) cm wide, glabrous; ocreae 0. Inflorescence: terminal, cyme-like; peduncles 0; involucre 1, (2)3--6(8) mm, tubular; basal awns 3, 0.2--2 mm, teeth 5, each with 0.3--1 mm awn. Flower: 2, 2--3(3.5) mm, hairy; perianth white to pink, lobes 6, 2-lobed; stamens 9. Fruit: brown, obconic, 2--2.5 mm, glabrous; embryo curved. Chromosomes: n=19.
Ecology: Common. Sand or gravel; Elevation: 300--2400 m. Bioregional Distribution: s SnJV, e SCoRI, TR, SNE, D; Distribution Outside California: to Utah, Arizona, northwestern Mexico. Flowering Time: Mar--Jul
Synonyms: Centrostegia thurberi var. macrotheca (J.T. Howell) Goodman; Chorizanthe thurberi (A. Gray) S. Watson; Chorizanthe thurberi var. cryptantha Curran; Chorizanthe thurberi var. macrotheca J.T. Howell
Jepson eFlora Author: James L. Reveal & Thomas J. Rosatti
Index of California Plant Names (ICPN; linked via the Jepson Online Interchange)

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Botanical illustration including Centrostegia thurberibotanical illustration including Centrostegia thurberi

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Citation for this treatment: James L. Reveal & Thomas J. Rosatti 2012, Centrostegia thurberi, in Jepson Flora Project (eds.) Jepson eFlora,, accessed on July 14, 2024.

Citation for the whole project: Jepson Flora Project (eds.) 2024, Jepson eFlora,, accessed on July 14, 2024.

Centrostegia thurberi
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©2009 Keir Morse
Centrostegia thurberi
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©2016 Keir Morse
Centrostegia thurberi
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©2009 Steve Matson
Centrostegia thurberi
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©2011 Steve Matson
Centrostegia thurberi
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©2014 James Morefield

More photos of Centrostegia thurberi
in CalPhotos

Geographic subdivisions for Centrostegia thurberi:
s SnJV, e SCoRI, TR, SNE, D
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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).