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Key to families | Table of families and genera
This text currently parallels The Jepson Manual: Vascular Plants of California, Second Edition that is now available at the University of California Press.
Text appearing in blue on this page will not appear in the printed book; it will be displayed only on the Web. Specimen numbers are hyperlinked to records in the Consortium of California Herbaria data view where possible. Taxa are hyperlinked to entries in the Jepson Interchange via the "[Online Interchange]" link.
Annual, perennial herb, glabrous.
Stem: generally > 1, erect, 2–100 cm, 3-sided or cylindric.
Leaf: basal; blade 0 or linear.
Inflorescence: terminal, generally ± umbel-like, with spikes on rays; inflorescence bracts 1–9, leaf-like, spreading or erect; rays <= 20 cm; spikelets flat to not flat; flower bracts 2-ranked, 2–36, each with 1 flower in axil.
Flower: bisexual; perianth 0; stamens (1–2) 3; stigmas 2–3.
Fruit: (ob) ovoid, generally 3-angled, brown, generally not beaked.
± 600 species: temps, tropics worldwide. (Greek: name for Eur Cyperus longus) [Tucker 1994 Syst Bot Monogr 43:1–213] Mature fruit generally needed for identification. Cyperus gracilis R. Br., Cyperus owanii Boeck. [Cyperus ligularis L., misappl.], Cyperus regiomontanus Britton, Cyperus retrorsus Chapm., Cyperus virens Michx., urban weeds in CA. Cyperus prolifer Lam. not in CA.
1. St 1; stolons with tubers; fruit seldom maturing
2. Fl bracts purple to red-brown, medially green ..... C. rotundus
2' Fl bracts yellow- to dark brown, medially ± brown, ± red, or ± green ..... C. esculentus
3. Spikelets ascending-erect; flower bract deltate-ovate ..... var. heermannii
3' Spikelets spreading to ± ascending; flower bract ovate to lance-ovate
4. Spikelets (1.2)1.5–2 mm wide; flower bract 1.8–2.7 mm; anthers (1)1.3(6) mm; styles (0.7)1–1.2 mm; stigmas (1.2)1.8(5) mm; common, CA ..... var. leptostachyus
4' Spikelets 2.4–3 mm wide; flower bract (2.7)2.9–3.4(3.6) mm; anthers (1.2)1.3–2(2.1) mm; styles (0.9)1.3–2(2.2) mm; stigmas (2)2.3–2.8(4) mm; not common, possibly only historical, SCo ..... var. macrostachyus
1' Sts generally > 1, clumped or not; stolons 0, tubers 0; fruit maturing
5. Fr 2-sided; stigmas 2
6. Fr face next to spikelet axis ..... C. laevigatus
6' Fr edge next to spikelet axis
7. Fl bracts ± yellow; fruit generally transverse-wrinkled ..... C. flavescens
7' Fl bracts light brown to red-brown, deep red, or black; fruit generally fine-pitted but not transverse-wrinkled
8. Lateral veins of flower bract 1–2; flower bracts spreading ..... C. flavicomus
8' Lateral veins of flower bract 0; flower bracts appressed
9. Annual; rhizomes 0; spikelets in open spikes; flower bracts brown to red-brown; fruit (ob)ovoid ..... C. bipartitus
9' Perennial; rhizomes short; spikelets generally in dense spikes; flower bracts light brown to black; fruit ovoid to elliptic ..... C. niger
5' Fr 3-sided; stigmas 3
10. Fl bract tips some or all distinctly outcurved, narrow-acute or bristle-like
11. Fl bract 3-veined, tip narrow-acute; fruit widest near middle ..... C. acuminatus
11' Fl bract 5–11-veined, tip bristle-like; fruit widest near tip ..... C. squarrosus
10' Fl bract tips not distinctly outcurved, acute, obtuse, or rounded, mucronate or not but not bristle-like
12. Basal leaf blades 0; inflorescence bracts (10)14–22 ..... C. involucratus
12' Basal leaf blades present; inflorescence bracts 1–12
13. Fl bract < 1.1 mm; plant annual; rhizomes 0
14. Spikelets 50–100+ ..... C. difformis
14' Spikelets 3–15 ..... C. fuscus
13' Fl bract 1.3–4 mm; plant annual, perennial herb; rhizomes often present
15. Fr body ± as long as wide
16. Fl bracts lance-ovate, acute ..... C. eragrostis
16' Fl bracts obovate to round, notched with point <= 0.12 mm ..... C. iria
15' Fr body 1.5–3 × longer than wide
17. Spikelets flat; flower bract red, red-purple, or red-brown ..... C. parishii
17' Spikelets not to ± flat; flower bract ± red to straw, brown, or tan
18. Fl bract 1.3–1.5 mm; fruit 0.7–1 mm ..... C. erythrorhizos
18' Fl bract 2–4 mm; fruit 1.5–2.4 mm
19. Annual; stem base not thickened or corm-like; flower bract persistent, ± red to straw, brown, or tan; spikelet axis jointed at each bract, spikelet falling apart ..... C. odoratus
19' Perennial; stem base thickened, corm-like; flower bract persistent or not, straw to pale brown; spikelet axis continuous, spikelet falling as unit ..... C. strigosus
Citation for the whole project: Jepson Flora Project (eds.) [year] Jepson eFlora, http://ucjeps.berkeley.edu/IJM.html [accessed on month, day, year]
Citation for an individual treatment: [Author of taxon treatment] [year]. [Taxon name] in Jepson Flora Project (eds.) Jepson eFlora, [URL for treatment]. Accessed on [month, day, year].
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