|Jepson Flora Project: Jepson Interchange|
|TREATMENT FROM THE JEPSON MANUAL (1993)||
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Jepson Interchange (more information)
©Copyright 1993 by the Regents of the University of California
AND IS MAINTAINED FOR ARCHIVAL PURPOSES ONLY
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 23-branched
Fruit: achene, generally 3-sided
Genera in family: ± 110 genera, 3600 species: worldwide, especially temp
Reference: [Tucker 1987 J Arnold Arbor 68:361445]
Difficult: taxa differ in technical characters of inflorescence and fruit.
Perennial, cespitose or from rhizomes, generally monoecious
Stem generally sharply 3-angled, generally solid
Leaves 3-ranked, generally glabrous except generally scabrous on midrib, margin; sheath closed, back (blade side of stem) green, ribbed, front generally thin, translucent, forming generally U-shaped mouth at top
Inflorescence: spikelets generally severalmany, arrayed in raceme, panicle, or head-like cluster, each 1many-flowered, generally subtended by a spikelet bract
Flowers unisexual, each subtended by 1 flower bract; perianth 0
Staminate flower: stamens generally 3
Pistillate flower enclosed by perigynium (sac-like bract); perigynium body 23-sided or round, wall generally delicate; perigynium beak tip open, often notched; style 1, generally deciduous, stigmas 24, exserted
Etymology: (Latin: cutter, from sharp leaf and stem edges)
Reference: [Standley 1985 Syst Bot Monogr 7:1106]
Fully mature perigynia needed for identification, so are described under "FR" (long-persistent perigynia are often atypical); perigynium "front" faces spikelet axis; "fruit" refers to achene body (excluding beak). "Shredding" lower leaf sheath fronts become a network or fringe of veins; some others shred longitudinally only. Difficult because of many species and minute key characters; longer key statements and descriptions are designed to enhance both ease and probability of correct identification. Group descriptions are assumed in specific descriptions
Horticultural information: Many species especially those with rhizomes are INVASIVE. This is one of the most effective genera for knitting moist or wet soil.
Stem often supported by vegetation
Leaf: blade 1.34.5 mm wide
Inflorescence ± dense, 1335 mm; lowest internode generally < lowest spikelet, lowest 2 together < 11 mm, 2/5 inflorescence length; lower spikelets generally distinct, wedge-shaped or rounded; lowest spikelet bract often bristle-like, generally > lowest spikelets, < or > inflorescence, base around stem; pistillate bract generally > 3.4 mm, < or > perigynium, reddish
Fruit: perigynium ascending, 2.95.5 mm, ± 1.32.2 mm wide, planoconvex, generally gold with brown margin, metallic, margin including wing < 0.3 mm wide, serrate on upper 1/2 body, wall ± tough, back veined, veins on front 07, to fruit top, beak generally ± 2/5 perigynium length, tip cylindric and ± entire for > 0.4 mm, brown to red-brown, 1.52.5 mm to fruit top; fruit 1.52.1 mm, 0.91.7 mm wide
Ecology: At least seasonally moist soil, grasslands to open forests
Elevation: < 900 m.
Bioregional distribution: North Coast, North Coast Ranges, Central Coast, San Francisco Bay Area, South Coast Ranges.