Common Name: BUCKTHORN FAMILY 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.
Common Name: BUCKTHORN Habit: 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 pls, 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. Etymology: (Greek: name for plants of this genus) Note: W.H. Brewer collected Rhamnus cathartica L., considered invasive in parts of United States, in 1861, but it apparently never naturalized. Other taxa in TJM (1993) moved to Frangula. eFlora Treatment Author: John O. Sawyer, Jr. Reference: Bolmgren & Oxelman 2004 Taxon 53:383--390 Unabridged Reference: Wolf 1938 Rancho Santa Ana Bot Gard Monogr 1
Rhamnus crocea Nutt.
NATIVE Habit: Shrub, < 2 m. Stem: bark gray; branches many, spreading, stiff, rooting; twigs +- thorn-tipped, red or red-purple. Leaf: evergreen; petiole 1--4 mm; blade 10--15 mm, elliptic to obovate, thick, glabrous, abaxially flat, base acute to rounded, tip rounded, margin sharp-toothed or entire, veins not prominent. Inflorescence: 1--6-flowered, glabrous; pedicel 1--6 mm. Flower: generally unisexual; hypanthium +- 2 mm wide; sepals 4; petals 0. Fruit: 2-stoned, 6 mm, red. Ecology: Coastal-sage scrub, chaparral, woodland; Elevation: < 1150 m. Bioregional Distribution: KR, NCoRO, SNH, CW, SW; Distribution Outside California: Baja California. Flowering Time: Jan--Apr Unabridged Note:Rhamnus crocea and its closely related species were considered conspecific by C.B. Wolf (1938) (e.g., Rhamnus crocea subsp. crocea, Rhamnus crocea subsp. ilicifolia, Rhamnus crocea subsp. pilosa, Rhamnus crocea subsp. pirifolia). Another, Rhamnus insula Kellogg (Rhamnus insula subsp. insula (Kellogg) C.B. Wolf) is restricted to Mexico (Baja California). The species are distinctive but intermediates exist. C.B. Wolf (1938) identified Rhamnus crocea/ilicifolia intermediates from Marin Co. to the California/Mexicoico boundary; Rhamnus ilicifolia/insula, Rhamnus crocea/pilosa, and Rhamnus ilicifolia/pilosa intermediates occur in southern California, especially in San Diego Co. Clearly, the Rhamnus crocea complex in California needs studies using modern techniques. Jepson eFlora Author: John O. Sawyer, Jr. Reference: Bolmgren & Oxelman 2004 Taxon 53:383--390 Index of California Plant Names (ICPN; linked via the Jepson Online Interchange) Previous taxon: Rhamnus alnifolia Next taxon: Rhamnus ilicifolia
Citation for this treatment: John O. Sawyer, Jr. 2012, Rhamnus crocea, in Jepson Flora Project (eds.) Jepson eFlora, https://ucjeps.berkeley.edu/eflora/eflora_display.php?tid=41069, accessed on February 06, 2025.
Citation for the whole project: Jepson Flora Project (eds.) 2025, Jepson eFlora, https://ucjeps.berkeley.edu/eflora/, accessed on February 06, 2025.
Geographic subdivisions for Rhamnus crocea:
KR, NCoRO, SNH, CW, SW
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(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).
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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).