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

  • Up-to-date information about California vascular plants is available from the Jepson eFlora.



Robert L. Schlising

Annual, perennial herb, generally monoecious; hairs often hardened by calcium deposits
Stems trailing or climbing, 1–many; tendril generally 1 per node, often branched
Leaves generally simple, alternate, generally palmately lobed, veined, petioled; stipule 0
Inflorescences at nodes; staminate flowers in racemes, panicles, small clusters, rarely solitary; pistillate flowers generally solitary
Flower unisexual in CA, radial; hypanthium > ovary; calyx (apparently 0 or) generally 5-lobed; corolla rotate or cup-shaped, generally 5-lobed; stamens 3–5 (or appearing 1–3 from fusion), anthers often > filaments, twisted together; ovary ± inferior, chambers generally 5, placentas parietal, ± growing into chambers, styles 1–3, stigmas generally lobed, large
Fruit: berry (sometimes drying) or capsule (irregularly dehiscent), generally gourd- or melon-like
Seeds 1–many
Genera in family: 100 genera, 700 species: especially tropical; some cultivated (Citrullus ; Cucumis ; Cucurbita ; Sechium , chayote). Citrullus colocynthis var. lanatus has been reported as a weed in DSon.



Perennial, sometimes temporarily dioecious; tuber large
Stem ± scabrous or hairy, becoming glabrous; tendril branched
Leaf ± round, cordate, ± 5–7-lobed
Inflorescences: staminate flowers in racemes or panicles with nonglandular axes (or 1 flower per axil early in season); pistillate flower 1 per axil (generally same axil as staminate)
Flower: sepals 0; corolla 3–15 mm wide (wider in pistillate), cup-shaped to rotate, white or cream to yellowish green; stamens fused, anthers twisted together; stigma 1, ± hemispheric
Fruit: capsule, irregularly dehiscent, ± symmetric, 3–20 cm, round, ovate, or oblong, sometimes tapered to a beak, ± prickly
Seed generally > 1 cm
Species in genus: 7 species: w North America
Etymology: (Hebrew: bitter, from taste of all parts)
Reference: [Schlising 1969 Amer J Bot 56:552–561]
Extremely variable in habit, leaves, sexual expression; presumed hybrids occur where species overlap. Sometimes included in Echinocystis.


M. macrocarpus (Greene) Greene

Herbage not glaucous
Flower: corolla shallowly cup-shaped, white
Fruit 5–12 cm, oblong, generally rounded at both ends (sometimes with sharp beak); prickles ± dense, stiff
Seeds generally 4–12(24), 13–33 mm, ± round, oblong, or ovate, angled at tip or not
Chromosomes: 2n=32,64
Ecology: Washes, shrubby or open areas
Elevation: < 900 m.
Bioregional distribution: Southwestern California, Sonoran Desert
Distribution outside California: Baja California

previous taxon | next taxon
bioregional map for MARAH%20macrocarpus being generated

Retrieve Jepson Interchange Index to Plant Names entry for Marah macrocarpus
Retrieve dichotomous key for Marah
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

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