Jepson eFlora: Taxon page
Vascular Plants of California
Key to families | Table of families and genera
Previous taxon Index to accepted names and synonyms:
| A | B | C | D | E | F | G | H | I | J | K | L | M |
| N | O | P | Q | R | S | T | U | V | W | X | Y | Z |
Next taxon

Sidotheca trilobata

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: SidothecaView DescriptionDichotomous Key

Habit: Annual, generally spreading, glabrous or glandular. Leaf: basal, linear to narrow, hairy, glandular, awns 0; ocreae 0. Inflorescence: terminal, cyme-like; peduncle erect to spreading; involucre 1, tubular, teeth 5(6), awned. Flower: 2--5(10), hairy, glandular; perianth white to rose or green-yellow to red, lobes 6, 3-lobed to fringed; stamens 9. Fruit: brown, obconic, glabrous; embryo curved.
Species In Genus: 3 species: western North America. Etymology: (Greek: star case, for involucre)
eFlora Treatment Author: James L. Reveal & Thomas J. Rosatti
Sidotheca trilobata (A. Gray) Reveal
Habit: Plant 0.7--5 dm, 0.7--6(11) dm diam. Leaf: blades 1--5(9) cm, 0.2--0.7(2) cm wide, linear or narrow. Inflorescence: bract awns 0.8--1 mm; peduncles erect to spreading, 0.5--1.5 cm, glabrous, glandular proximally; involucre 3--8 mm, glandular, teeth 5(6), awns 0.3--2 mm, +- green to +- red. Flower: 3--5(10), 2.5--4 mm; perianth white to pink or +- red, lobes 3-lobed. Fruit: 1.2--2 mm. Chromosomes: n=20.
Ecology: Common. Sand; Elevation: 700--2100 m. Bioregional Distribution: SnGb, SnBr, PR, w DMtns (Little San Bernardino Mtns); Distribution Outside California: Baja California. Flowering Time: Apr--Sep
Synonyms: Eriogonum trilobatum (A. Gray) S. Stokes; Oxytheca trilobata A. Gray
Jepson eFlora Author: James L. Reveal & Thomas J. Rosatti
Index of California Plant Names (ICPN; linked via the Jepson Online Interchange)

Previous taxon: Sidotheca emarginata
Next taxon: Systenotheca

Name Search

Botanical illustration including Sidotheca trilobata

botanical illustration including Sidotheca trilobata


Citation for this treatment: James L. Reveal & Thomas J. Rosatti 2012, Sidotheca trilobata, in Jepson Flora Project (eds.) Jepson eFlora, /eflora/eflora_display.php?tid=81336, accessed on May 31, 2020.

Citation for the whole project: Jepson Flora Project (eds.) 2020, Jepson eFlora,, accessed on May 31, 2020.

Sidotheca trilobata
click for enlargement
© 2015 Chris Winchell
Sidotheca trilobata
click for enlargement
© 2014 Keir Morse
Sidotheca trilobata
click for enlargement
© 2014 Keir Morse
Sidotheca trilobata
click for enlargement
© 2015 Chris Winchell
Sidotheca trilobata
click for enlargement
© 2014 Keir Morse
Sidotheca trilobata
click for enlargement
© 2014 Keir Morse

More photos of Sidotheca trilobata in CalPhotos

Geographic subdivisions for Sidotheca trilobata:
SnGb, SnBr, PR, w DMtns (Little San Bernardino Mtns)
1. You can change the display of the base map and layers by clicking on the layer control box in the upper right-hand corner.
2. California county polygons can be turned off and on in the layer control box.
3. Filling of Jepson subdivision polygons can be turned off and on in the layer control box.
4. Marker clustering can be turned on by clicking this link:      Marker Clustering ON
WARNING: This page may load slowly if there are large numbers of specimens in the database.
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 occurence).


View elevation by latitude chart

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

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).