Jepson Flora Project: Jepson Interchange    

 
link to manual TREATMENT FROM THE JEPSON MANUAL (1993) previous taxon | next taxon
Jepson Interchange (more information)
©Copyright 1993 by the Regents of the University of California

    THIS PAGE IS NO LONGER UPDATED
    AND IS MAINTAINED FOR ARCHIVAL PURPOSES ONLY
  • Up-to-date information about California vascular plants is available from the Jepson eFlora.

RHAMNACEAE

BUCKTHORN FAMILY

John O. Sawyer, Jr. (except Ceanothus)

Shrub, vine, tree, generally erect, often thorny
Leaves simple, generally alternate, often clustered on short-shoots, generally petioled, generally stipuled; blade often 1–3-ribbed from base
Inflorescence: cyme, panicle, or flowers solitary in axils
Flower generally bisexual, radial; hypanthium subtending, surrounding, or partly fused to ovary; sepals 4 or 5; petals 0, 4, or 5, clawed; stamens 4 or 5, alternate sepals, attached to hypanthium top, each generally fitting into a petal concavity; ovary superior or partly inferior, chambers 2–5, each 1–2-ovuled, style lobes or parts 1–3
Fruit: capsule, drupe
Genera in family: 55 genera, 900 species: especially tropical, subtropical; some cultivated (Ceanothus ; Colletia , anchor-plant; Gouania ; Phylica ; Rhamnus ; Ventilago ; Ziziphus )
Reference: [Brizicky 1965 J Arnold Arbor 45:439–463]

RHAMNUS

BUCKTHORN

Shrub, small tree
Stem: branches alternate, flexible; twigs sometimes thorn-tipped
Leaves sometimes clustered on short-shoots, deciduous or evergreen, petioled; stipules deciduous; blade 1-ribbed from base, entire or not
Inflorescence: umbel or flowers solitary, axillary
Flower bisexual or unisexual, generally < 3 mm; hypanthium at base fused to, developing around ovary in fruit, above base deciduous; sepals 4 or 5; petals 0, 4, or 5; stamens 4 or 5; ovary appearing partly inferior, chambers 2–4, each 1–2-ovuled, style lobes 2–4
Fruit: drupe, 2–4-stoned
Species in genus: 125 species: temp, few tropical
Etymology: (Greek: name for plants of this genus)
Reference: [Wolf 1938 Rancho Santa Ana Bot Gard Monogr 1]
Some of value in medicine or as dyes.

Native

R. purshiana DC.

CASCARA

Tree or shrub, < 12 m
Stem: bark gray; twigs red to brown; terminal bud not covered with scales, hairs brown
Leaves deciduous; petiole 6–23 mm; blade 50–150 mm, broadly elliptic to obovate, thin, base obtuse or tapered, tip obtuse to truncate, margin irregularly toothed to entire, surfaces sparsely hairy to glabrous, veins prominent
Inflorescence < 25-flowered; pedicels < 25 mm
Flower bisexual; hypanthium 3 mm; sepals 5; petals 5; stamens 5; style included
Fruit 3-stoned, 10 mm, black
Ecology: Coniferous forests, chaparral
Elevation: < 2000 m.
Bioregional distribution: North Coast, Klamath Ranges, Outer North Coast Ranges, High North Coast Ranges, Cascade Range, n&c Sierra Nevada
Distribution outside California: to British Columbia, Montana
Plants with wedge-shaped leaves in KR, CaR, n&c SN assignable with difficulty to var. annonifolia (Greene) Jeps. Bark yields cathartic drugs; bark and fruit TOXIC in excess, especially to children
Horticultural information: 4, 5 &IRR: 1, 2, 3, 6, 16, 17 &SHD: 7, 14, 15.

previous taxon | next taxon
bioregional map for RHAMNUS%20purshiana being generated
 


Retrieve Jepson Interchange Index to Plant Names entry for Rhamnus purshiana
Retrieve dichotomous key for Rhamnus
Overlay Consortium of California Herbaria specimen data by county on this map
Show other taxa with the same California distribution | Read about bioregions | Get lists of plants in a bioregion
Return to the Jepson Interchange main page
Return to treatment index page
Glossary


University & Jepson Herbaria Home Page |
General Information | University Herbarium | Jepson Herbarium |
Visiting the Herbaria | On-line Resources | Research |
Education | Related Sites
Copyright © by the Regents of the University of California