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.



Lauramay T. Dempster

Perennial (sometimes annual, shrub, vine, tree); sap milky
Leaves simple, entire, opposite, alternate, or subwhorled; stipules 0 or small
Inflorescence: cyme; flowers 1–many, axillary or terminal
Flower bisexual, radial; perianth parts overlapping, at least in bud; sepals 5, fused at base, persistent; petals 5, fused in ± basal half; stamens 5, attached to corolla tube or throat, alternate lobes; ovaries 2, ± superior, generally free, styles and stigmas fused
Fruit: generally 2 follicles
Seeds many, often with tuft of silky hairs
Genera in family: ± 150–200 genera, 1000–2000 species: especially tropical; many ornamental (Nerium, oleander; Plumeria , frangipani); some alkaloids highly toxic, some used in medicine
Recent taxonomic note: Recently treated to include Asclepiadaceae
Reference: [Rosatti 1989 J Arnold Arbor 70:307–401]


Plant erect
Stem ± woody
Leaves alternate to subwhorled
Inflorescence: flowers several–many
Flower: corolla salverform; anthers free from each other and stigma; nectary 0 or low ring around ovaries; style ± thread-like, stigma skirted at base
Seed glabrous
Species in genus: 5–25 species: North America, Japan
Etymology: (Probably for Charles Amson, Virginian physician, 18th century)
Reference: [McLaughlin 1982 Ann Missouri Bot Gard 69:336–350]


A. tomentosa Torr. & Frémont

Plant glabrous or grayish tomentose
Stems several–many from woody crown, 16–36 cm
Leaf 2–4 cm; petiole short or 0; blade ovate-lanceolate
Flower: calyx lobes erect, thread-like above base; corolla whitish, blue, or greenish, tube ± 15 mm, inflated above middle, narrower just below spreading lobes; style spheric just below stigma
Fruit 3–8 cm, narrowed between seeds, often breaking into 1-seeded segments
Ecology: Desert plains, canyons
Elevation: 300–1800 m.
Bioregional distribution: San Bernardino Mountains (n slope), s Desert Mountains, Sonoran Desert
Distribution outside California: to Utah
Flowering time: Mar–May
Synonyms: A. brevifolia A. Gray
Hairiness is probably a simple, genetically recessive trait
Horticultural information: TRY.

previous taxon | next taxon
bioregional map for AMSONIA%20tomentosa being generated

Retrieve Jepson Interchange Index to Plant Names entry for Amsonia tomentosa
Retrieve dichotomous key for Amsonia
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