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, small tree, < 10 m.
Stem: branches alternate, stiff or flexible; twigs generally not thorn-tipped; winter bud scales present, generally ± 3 mm.
Leaf: scattered along branches or clustered on short- shoots, deciduous or evergreen; stipules generally deciduous; petioles generally glabrous; blade veins prominent or not.
Inflorescence: flowers 1 or in cyme-like clusters in axils.
Flower: unisexual ( bisexual), generally on separate plants, generally < 3 mm; hypanthium bell-shaped to cup-like, 2–3 mm wide; sepals 4–5, thin, spreading, not keeled adaxially; petals 0 or 4–5; disk thin, adhering to hypanthium; ovary appearing superior or partly inferior, chambers 2–4, each 1-ovuled, style 1, stigma 2–4-lobed.
Fruit: drupe, 2–3[4]-stoned.
110 species: temperate, few tropics; some of value in medicine or as dyes. (Greek: name for plants of this genus) [Bolmgren & Oxelman 2004 Taxon 53:383–390] W.H. Brewer collected Rhamnus cathartica L., considered invasive in parts of US, in 1861, but it apparently never naturalized. Other taxa in TJM (1993) moved to Frangula.
Unabridged references: [Wolf 1938 Rancho Santa Ana Bot Gard Monogr 1]

Small tree, < 10 m.
Stem: bark gray; branches ascending; twigs purple.
Leaf: evergreen; petiole 5–10 mm; blade 20–50 mm, elliptic, thick, glabrous, abaxially concave, base rounded, tip acute to rounded, mucronate, margin entire to toothed, veins prominent.
Inflorescence: 1–6-flowered, glabrous; pedicels 3–6 mm.
Flower: generally unisexual; hypanthium ± 2 mm wide; sepals 4; petals 0.
Fruit: 2-stoned, 6–8 mm, red.
Coastal-sage scrub, chaparral; 10–520 m. Channel Islands;

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Next taxon: Ziziphus

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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.