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    THIS PAGE IS NO LONGER UPDATED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.

AMARANTHACEAE

AMARANTH FAMILY

James Henrickson

Annual to tree
Stem prostrate to erect
Leaves alternate or opposite, simple, generally entire, bract-like upward; stipules 0
Inflorescence: cymes, often arrayed ± in spikes or panicles; bracts 1–3 per flower, generally membranous-scarious, tip often short-pointed or spine-like
Flower generally small, uni- or bisexual, radial; sepals 0–5, fused at base or free, often ± scarious; petals 0; stamens 0–5, opposite sepals (staminodes sometimes alternating), filaments sometimes fused at base; ovary superior, 1-chambered, ovules 1–several, erect or pendent on ± basal stalks, styles 0–3, stigma head-like or 2–3-lobed
Fruit: utricle to circumscissile capsule
Seed lenticular to spheric, hard
Genera in family: ± 65 genera, ± 900 species: tropical, subtropical
Reference: [Robertson 1981 J Arnold Arbor 62:267–313]

AMARANTHUS

PIGWEED, AMARANTH

Annual, monoecious or dioecious
Leaves alternate; blade linear to ovate
Inflorescence: cymes in dense, spike-like clusters; bract 1, tip generally short-pointed or -spined, generally scarious; bractlets 0–2
Staminate flower: sepals 3–5, ± equal, ± as bracts; stamens (1)3–5, filaments free; staminodia 0
Pistillate flower: sepals (3–)5, ± equal, scarious except midvein, fused at base, falling with fruit; ovary compressed-ovoid, styles (2)3, stigmas slender, papillate, ovule 1, erect
Fruit circumscissile or indehiscent, smooth or inflated-wrinkled; walls membranous to spongy-hardened
Seed 1, lenticular, smooth, reddish to black
Species in genus: ± 60 species: worldwide; some potherbs, some cultivated for seed
Etymology: (Greek: unfading, from persistent bracts and sepals)
Some species (especially A. cruentus, A. powellii, A. retroflexus) hybridize complexly
Reference: [Tucker & Sauer Madroño 1958 14:252–261]

Native

A. fimbriatus (Torr.) Benth.

Plant erect, 4–10 dm, often reddish, monoecious
Leaf: petiole 5–20 mm; blades 20–100 mm, linear to narrowly lanceolate
Inflorescence: lower clusters axillary, scattered; terminal clusters spike-like, 10–30 cm, 1–2 cm wide, crowded, leafy; bracts 1–1.8 mm, scarious (except midrib)
Staminate flower: sepals 5, 1–1.5 mm; stamens 3
Pistillate flower: sepals 5, 1.5–3.3 mm, < or = 2.5 mm wide, subequal, fan-shaped, tip long-toothed, fringed, reflexed
Fruit ± 1.5 mm, circumscissile; lid strongly inflated-wrinkled near base
Seed 0.9–1 mm wide
Chromosomes: n=17
Ecology: Common. Sandy, gravelly slopes, washes, after summer rains
Elevation: 600–1700 m.
Bioregional distribution: Desert
Distribution outside California: to s Canada, Montana, w Texas, Baja California
Flowering time: Aug–Nov

previous taxon | next taxon
bioregional map for AMARANTHUS%20fimbriatus being generated
 


Retrieve Jepson Interchange Index to Plant Names entry for Amaranthus fimbriatus
Retrieve dichotomous key for Amaranthus
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