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.

    THIS PAGE IS NO LONGER UPDATED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.

CYPERACEAE

SEDGE FAMILY

Raymond Cranfill, except as specified

Annual or perennial herb, often rhizomed, often of wet open places, generally monoecious; roots fibrous, hairy
Stem generally 3-sided
Leaves often 3-ranked; sheath generally closed; ligule generally 0; blade (0) various, parallel-veined
Inflorescence: spikelets variously clustered; flowers generally sessile in axil of flower bract
Flower small, generally wind-pollinated; perianth 0 or bristle-like; stamens generally 3, anthers attached at base, 4-chambered; ovary superior, 1-chambered, 1-ovuled, style 2–3-branched
Fruit: achene, generally 3-sided
Genera in family: ± 110 genera, 3600 species: worldwide, especially temp
Reference: [Tucker 1987 J Arnold Arbor 68:361–445]
Difficult: taxa differ in technical characters of inflorescence and fruit.

ELEOCHARIS

SPIKERUSH

Annual or perennial herb
Stem generally round, ridged and grooved, generally solid
Leaves basal, 1(–4); base sheathing; blade generally 0
Inflorescence: spikelet solitary, terminal, erect; spikelet bract 0; flower bracts generally spiraled
Flowers bisexual; perianth bristles 0–6, persistent, barbs generally recurved; stamens (1–)3; style 2–3-branched, base bulb-like, persistent
Fruit 2–3-sided or round; top tubercled
Species in genus: ± 250 species: worldwide
Etymology: (Greek: marsh grace)
St shape best seen in fresh material (or just below spikelet); drying exaggerates ridges and grooves.

Native

E. obtusa (Willd.) Schult.

Annual < 5 dm
Stem spongy, flattened in pressing
Leaf purplish below, becoming straw-colored above; tip oblique, entire
Inflorescence: spikelet 2–16 mm, often wider than stem, oblong to ± round, tip obtuse, generally 10–many-flowered; flower bract ovate, brownish, tip obtuse to acute
Flower: style 2-branched
Fruit: perianth bristles < to > fruit; body ± 1–1.5 mm, ± obovoid, 2-sided, (pale) brown, shiny; tubercle flat, base not narrowed
Chromosomes: 2n=10
Ecology: Wet soil of pond and lake margins, marshes, often yellow-pine forests
Elevation: < 2600 m.
Bioregional distribution: Northwestern California, Sierra Nevada, Modoc Plateau
Distribution outside California: to British Columbia, Idaho, e N.America
Also e North America, with other vars.

Native

var. obtusa


Inflorescence: spikelet 2–13 mm, ± round, tip ± obtuse
Fruit: perianth bristles > fruit; tubercle 1/3–1/2 fruit body
Ecology: Habitats of sp.
Elevation: < 1000 m.
Bioregional distribution: Northwestern California
Distribution outside California: to British Columbia, Idaho; also e N.America

previous taxon | next taxon
bioregional map for ELEOCHARIS%20obtusa%20var.%20obtusa being generated
 


Retrieve Jepson Interchange Index to Plant Names entry for Eleocharis obtusa var. obtusa
Retrieve dichotomous key for Eleocharis
Return to treatment index page
Glossary
University & Jepson Herbaria Home Page | Copyright © by the Regents of the University of California