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
For up-to-date information about California vascular plants, visit the Jepson eFlora.



Richard Spellenberg

Perennial, shrub, tree, glabrous or hairy
Stem often forked
Leaves opposite, sessile or petioled, pairs generally unequal; blade generally entire
Inflorescence generally forked; of spikes, clusters, or umbels, each unit sometimes with a calyx-like involucre
Flower bisexual, radial; perianth of 1 whorl, petal-like, bell- to trumpet-shaped, base hardened, tightly surrounding ovary in fruit, lobes 4–5, generally notched to ± bilateral; stamens 1–many; ovary superior (appearing inferior because of hardened perianth base), style 1
Fruit: achene or nut, smooth, wrinkled, or ribbed
Genera in family: 30 genera, 300 species: warm regions, especially Am; some ornamental (Bougainvillea ; Mirabilis , four o'clock).


Perennial from large taproot
Stem much-branched
Leaf petioled; blade < 8 cm, fleshy, margin often wavy
Inflorescence: head; bracts 5–10, green, flowers blooming sequentially across head; receptacle flat to ± conic, studded with peg-like pedicels
Flower: perianth trumpet-shaped, nocturnal, lobes 4–5; stamens 3–5, included; stigma linear, included
Fruit: wings 3–5, wide, continuous above and below fruit body, thin, transparent, conspicuously net-veined
Species in genus: 3 species: arid North America
Etymology: (Greek & Latin: 3-winged cup, from fruit)
[Galloway 1977 Brittonia 27:328–347] Closely related to Abronia.


T. micranthus (Torr.) Hook.

Stem < 6 dm, glandular-sticky or scabrous
Leaf: blade 1–6 cm, narrowly ovate to elliptic, glabrous to glandular-hairy, hairs denser on lower surface
Flower: perianth 6–18 mm
Fruit: wings glabrous except on edges
Ecology: Dunes
Elevation: 800–2450 m.
Bioregional distribution: se Mojave Desert (Kelso, San Bernardino Co.)
Distribution outside California: to Montana, South Dakota, New Mexico
Flowering time: Apr–May
Synonyms: Abronia m. Torr
Horticultural information: TRY.
See the CNPS Inventory for information about endangerment and rarity.
previous taxon | next taxon
bioregional map for TRIPTEROCALYX%20micranthus being generated
YOU CAN HELP US make sure that our distributional information is correct and current. If you know that a plant occurs in a wild, reproducing state in a Jepson bioregion NOT highlighted on the map, please contact us with that information. Please realize that we cannot incorporate range extensions without access to a voucher specimen, which should (ultimately) be deposited in an herbarium. You can send the pressed, dried collection (with complete locality information indicated) to us (e-mail us for details) or refer us to an accessioned herbarium specimen. Non-occurrence of a plant in an indicated area is difficult to document, but we will especially value your input on those types of possible errors (see automatic conversion of distribution data to maps).

Retrieve Jepson Interchange Index to Plant Names entry for Tripterocalyx micranthus
Retrieve dichotomous key for Tripterocalyx
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
  • This page is no longer being maintained.

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