Jepson eFlora
Key to families | Table of families and genera

Key to Cyperus

View taxon page for Cyperus

Jepson Manual glossary definitions can be seen by moving your cursor over words underlined with dots.

1. Stem 1; stolons with tubers; fruit seldom maturing

2. Flower bracts purple to red-brown, medially green ..... C. rotundus

2' Flower 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, California ..... 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, South Coast ..... var. macrostachyus

1' Stems generally > 1, clumped or not; stolons 0, tubers 0; fruit maturing

5. Fruit 2-sided; stigmas 2

6. Fruit face next to spikelet axis ..... C. laevigatus

6' Fruit edge next to spikelet axis

7. Flower bracts ± yellow; fruit generally transverse-wrinkled ..... C. flavescens

7' Flower 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 herb; rhizomes short; spikelets generally in dense spikes; flower bracts light brown to black; fruit ovoid to elliptic ..... C. niger

5' Fruit 3-sided; stigmas 3

10. Flower bract tips some or all distinctly outcurved, narrow-acute or bristle-like

11. Flower bract 3-veined, tip narrow-acute; fruit widest near middle ..... C. acuminatus

11' Flower bract 5–11-veined, tip bristle-like; fruit widest near tip ..... C. squarrosus

10' Flower 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. Flower bract < 1.1 mm; plant annual; rhizomes 0

14. Spikelets 50–100+ ..... C. difformis

14' Spikelets 3–15 ..... C. fuscus

13' Flower bract 1.3–4 mm; plant annual, perennial herb; rhizomes often present

15. Fruit body ± as long as wide

16. Flower bracts lance-ovate, acute ..... C. eragrostis

16' Flower bracts obovate to round, notched with point <= 0.12 mm ..... C. iria

15' Fruit 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. Flower bract 1.3–1.5 mm; fruit 0.7–1 mm ..... C. erythrorhizos

18' Flower 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 herb; 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, [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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