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



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.


S. Galen Smith, A.E. Schuyler, and William J. Crins

Annual or perennial herb, rhizomed or not; roots fibrous
Stem generally erect, 3-angled or cylindric, solid
Leaves basal or cauline, alternate, 3-ranked; sheaths closed; ligule 0 or present; blades linear, sometimes vestigial and scale-like
Inflorescence panicle- or head-like; bracts 1–several, leaf- or ± stem-like; spikelets 1–many, generally many-flowered; flower bracts spiraled, generally ovate, scale-like
Flower bisexual; perianth bristles generally < and hidden by flower bracts, generally ± straight, generally slender, generally stiff, generally persistent on fruit, generally finely spined or fringed, sometimes 0 or vestigial; stamens generally 3; style 1, ribbon- or thread-like, stigmas 2–3, generally exserted
Fruit: achene, generally obovoid, lenticular or ± 2–3-angled, generally beaked, not tubercled
Species in genus: ± 200 species: generally wet sites, worldwide. Some species mistaken for Eleocharis
Recent taxonomic note: *CA plants treated as Amphiscirpus, Bolboschoenus, Isolepis, Schoenoplectus, Trichophorum [Browning et al. 1995 Brittonia 47:433–445; Smith 1995 Novon 5:97–102]


S. acutus Bigelow var. occidentalis (S. Watson) Beetle


Perennial 150–400 cm; rhizome long
Stems erect, 4–12 mm wide in middle, cylindric
Leaves ± basal; sheaths prominent; blades 1–2, << sheaths, flat, glabrous
Inflorescence panicle-like; branches stiff to flexible, erect to arched; spikelets 3–many, in clusters of 1–7 at branch tips, 7–10(24) mm, 3–4.5 mm wide; main bract 1–4(11) cm, generally erect, stiff, stem-like at least above; flower bract ± 4 mm, finely prickly to papillate above middle, ± colorless to straw-colored, or orange to dark red-brown above, generally prominently spotted, margin woolly, tip notched, awn 0.5–1 mm, generally contorted
Flower: perianth bristles generally 6, < or = fruit; stigmas 2–3
Fruit 2–2.5 mm, obtusely 2–3-angled, smooth, gray-brown; beak 0.1–0.3 mm
Ecology: Marshes, lakes, streambanks
Elevation: < 2500 m.
Bioregional distribution: California
Distribution outside California: temperate N.America
Flowering time: May–Aug
Hybridizes with S. californicus, S. tabernaemontani ; some plants in mtns with < 40 spikelets per inflorescence, stigmas 2, fruit 2-angled, perianth bristles ± = fruit may be var. acutus (generally e North America).
Recent taxonomic note: *Schoenoplectus acutus (Bigelow) Á. Löve & D. Löve var. occidentalis (S. Watson) S.G. Sm.
Horticultural information: STBL.

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