Jepson Herbarium
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[Perennial] 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.
50–52 genera, 950 species: especially tropics, subtrop; some cultivated (Ceanothus; Frangula; Rhamnus; Ziziphus). [Richardson et al. 2000 Amer J Bot 87:1309–1324] —Scientific Editors: Steve Boyd, Thomas J. Rosatti.
Unabridged references: [Brizicky 1965 J Arnold Arbor 45:439–463; Richardson et al. 2000 Kew Bull 55:311–341]

Key to Rhamnaceae

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.
± 55 species: North America. (Greek: thorny plant) [Fross & Wilken 2006 Ceanothus. Timber Press] Hybrids common (named hybrids not recognized here), discussed in Fross & Wilken; hybrid forms do not key easily. As recircumscribed here, Ceanothus greggii A. Gray restricted to Mex.

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. [Online Interchange]

Stem: twigs ± red-brown, puberulent.
Leaf: blade adaxially short-hairy.
Flower: disk, ovary short-hairy.
Fruit: generally prominent-wrinkled.
Slopes, ridges, chaparral, conifer forest; 400–1500 m. Peninsular Ranges;

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Citation for the whole project: Jepson Flora Project (eds.) [year] Jepson eFlora, http://ucjeps.berkeley.edu/IJM.html [accessed on month, day, year]
Citation for an individual treatment: [Author of taxon treatment] [year]. [Taxon name] in Jepson Flora Project (eds.) Jepson eFlora, [URL for treatment]. Accessed on [month, day, year].

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Bioregions in which taxon occurs	Red area (if present) is the part of the bioregion lying between the upper and lower elevation limits of the taxon; markers link to CCH specimen records. If the markers are obscured, reload the page [or change window size and reload]. Yellow markers indicate records that may have georeferencing or identification issues.
Chart based on elevation range in Manual and elevations and coordinates of CCH records. Data provided by the participants of the Consortium of California Herbaria. Note: About half of the CCH records include both elevation and coordinates.	Map made in collaboration with Scott Loarie. 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. Blue line denotes Manual flowering time.