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Ceanothus oliganthus var. sorediatus

Higher Taxonomy
Family: RhamnaceaeView DescriptionDichotomous Key

Habit: [Perennial herb] shrub, tree, generally erect, often thorny. Leaf: simple, generally alternate, often clustered on short-shoots; stipules generally present, occasionally modified into spines; generally petioled; blade pinnate-veined or 1--5-ribbed from base. Inflorescence: cyme, panicle, umbel, or flowers 1 or clustered in axils or on short-shoots. Flower: generally bisexual, radial; hypanthium subtending, surrounding, or partly fused to ovary; sepals 4--5; petals 0, 4--5, generally clawed; stamens 0, 4--5, alternate sepals, attached to hypanthium top, each generally fitting into a petal concavity; disk (0 or) between stamens, ovary, thin to fleshy, entire or lobed, free from ovary, adherent or fused to hypanthium; ovary superior or +- inferior, chambers [1]2--4, 1--2-ovuled, style 1, stigma entire or 2--3-lobed. Fruit: capsule, drupe.
Genera In Family: 50--52 genera, 950 species: especially tropics, subtropics some cultivated (Ceanothus; Frangula; Rhamnus; Ziziphus).
eFlora Treatment Author: John O. Sawyer, Jr., except as noted
Scientific Editor: Steve Boyd, Thomas J. Rosatti.
Genus: CeanothusView DescriptionDichotomous Key

Habit: Shrub, tree-like or not, generally erect or mat- to mound-like. Stem: branches generally arranged like leaves; twigs thorn-like or not, generally not angled. Leaf: alternate or opposite, some clustered on short-shoots or not, deciduous or evergreen; stipules scale-like, thin, deciduous, or knob-like, corky, thick, base persistent; blade flat or wavy, tip generally acute to obtuse, margin thick (i.e., thicker than adjacent blade) or not, rolled under or not, wavy or not, entire or gland- or sharp-toothed, glands generally dark, teeth pale, alternate blade 1--3-ribbed from base, generally thin, opposite blade 1-ribbed from base, thick, firm. Inflorescence: umbel-, raceme-, or panicle-like aggregations of few-flowered clusters, axillary or terminal; pedicels white to deep blue or pink. Flower: conspicuous, generally < 5 mm; hypanthium surrounding fleshy disk below ovary base, in fruit thick, not splitting; sepals generally 5, lance-deltate, incurved, colored like petals, persistent; petals generally 5, blade hood-like, white to deep blue or pink; stamens generally 5, opposite petals; ovary 1/2-inferior, 3-lobed, chambers 3, each 1-ovuled, styles 3. Fruit: capsule, +- spheric, generally +- 3-lobed, generally smooth, 3-ridged or not, horned or not. Seed: 3, 2--5 mm.
Species In Genus: +- 55 species: North America. Etymology: (Greek: thorny pl) Note: Hybrids possibly common (named hybrids not recognized here), discussed in Fross & Wilken; possible hybrid forms do not key easily.
eFlora Treatment Author: Dieter H. Wilken & Dylan O. Burge
Reference: Fross & Wilken 2006 Ceanothus. Timber Press; Burge et al. 2015 Syst Bot 40:950--961.
Species: Ceanothus oliganthusView Description 

Habit: Plant erect, tree-like or not, open, < 3.5 m. Stem: ascending to erect; twigs flexible, not thorn-like, not angled. Leaf: alternate, evergreen; stipules scale-like; petiole 3--7 mm; blade 11--30 mm, 5--25 mm wide, ovate to elliptic, generally flat, adaxially dark green, +- glabrous to short-hairy, abaxially paler, sparsely to densely short-hairy, especially veins, margin minutely gland-toothed, teeth 20--70, glands +- spheric. Inflorescence: generally raceme-like, 1--5 cm. Flower: blue to purple-blue; disk, ovary glabrous or short-hairy. Fruit: 4--7 mm wide, generally sticky, +- ridged to bulged distally; horns 0.

Ceanothus oliganthus var. sorediatus (Hook. & Arn.) Hoover
Stem: twigs +- red-brown, +- glabrous. Leaf: blade adaxially glabrous to sparsely short-hairy. Flower: disk, ovary glabrous. Fruit: generally smooth. Chromosomes: 2n=24.
Ecology: Slopes, ridges, chaparral, conifer forest; Elevation: 60--1220 m. Bioregional Distribution: KR, NCoR, n SNH, CW, TR, PR. Flowering Time: Jan--May
Synonyms: Ceanothus sorediatus Hook. & Arn.;
eFlora Treatment Author: Dieter H. Wilken & Dylan O. Burge
Reference: Fross & Wilken 2006 Ceanothus. Timber Press; Burge et al. 2015 Syst Bot 40:950--961.
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Citation for this treatment: Dieter H. Wilken & Dylan O. Burge 2016, Ceanothus oliganthus var. sorediatus, in Jepson Flora Project (eds.) Jepson eFlora, Revision 4,, accessed on October 20, 2018.

Citation for the whole project: Jepson Flora Project (eds.) 2018, Jepson eFlora,, accessed on October 20, 2018.

Ceanothus oliganthus var. sorediatus
click for enlargement
© 2009 Barry Breckling
Ceanothus oliganthus var. sorediatus
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© 2013 Vernon Smith
Ceanothus oliganthus var. sorediatus
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© 2007 Toni Corelli
Ceanothus oliganthus var. sorediatus
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© 2017 Steve Matson
Ceanothus oliganthus var. sorediatus
click for enlargement
© 2009 Barry Breckling
Ceanothus oliganthus var. sorediatus
click for enlargement
© 2009 Barry Breckling

More photos of Ceanothus oliganthus var. sorediatus in CalPhotos

Geographic subdivisions for Ceanothus oliganthus var. sorediatus:
KR, NCoR, n SNH, CW, TR, PR.
Markers link to CCH specimen records. Yellow markers indicate records that may provide evidence for eFlora range revision or may have georeferencing or identification issues. Purple markers indicate specimens collected from a garden, greenhouse, or other non-wild location.
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

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.