Jepson eFlora
Key to families | Table of families and genera

Key to Cyperaceae

View taxon page for Cyperaceae

1. Flower, fruit enclosed in sac-like structure (perigynium); flowers unisexual

2. Perigynium open at tip ..... CAREX

2' Perigynium open on 1 side ..... KOBRESIA

1' Flower, fruit not enclosed in sac-like structure; flowers bisexual or some staminate

3. Flower bracts 2-ranked; spikelets generally flat

4. Inflorescence in leaf axils; leaves cauline; stem internodes hollow ..... DULICHIUM

4' Inflorescence terminal; leaves basal or basal and cauline; stem internodes solid or spongy with air cavities

5. Spikelets with >= 2 sterile proximal flower bracts; leaf sheaths ± black; inflorescence head-like ..... SCHOENUS

5' Spikelets with 0–1 sterile proximal flower bracts; leaf sheaths not ± black; inflorescence head-like to openly branched

6. Spikelets with 2–36 flower bracts, each bract subtending a bisexual flower; fruits 2–many per spikelet ..... CYPERUS

6' Spikelets with 2(3) flower bracts, proximal bract sterile or subtending a bisexual flower, distal sterile or subtending a staminate flower; fruits 1 per spikelet ..... KYLLINGA

3' Flower bracts spiraled (except Isolepis levynsiana); spikelets not flat (± flat in Isolepis levynsiana)

7. Flower stems generally with cauline leaves 0 (1–2 cauline in Schoenoplectus saximontanus)

8. Inflorescence bracts 0; spikelet 1; leaves 2, blade 0 or tooth-like, <= 1 mm; fruit tubercle generally present ..... ELEOCHARIS

8' Inflorescence bracts >= 1; spikelets >= 1; leaves 1–3, generally some clearly bladed; fruit tubercle 0

9. Flower bract (outer if 2) with >= 3 veins; stem <= 40 cm

10. Flower bract 1 per flower ..... ISOLEPIS

10' Flower bracts (1)2 per flower (a 2nd, inner bract between flower, spikelet axis generally present) ..... LIPOCARPHA

9' Flower bract with 1 vein, at least in distal-most part of spikelet; stem <= 400 cm

11. Stems <= 15 cm, < 1 mm diam; spikelets 1, 3–4.6 mm, 1.5–2.8 mm wide ..... TRICHOPHORUM

11' Stems (1)10–400 cm, <= 10 mm diam; spikelets 1–200, 3–23 mm, 2–7 mm wide

12. Ligule ciliate; stem, leaf air cavities 0; stem wiry; flower bracts shiny, in proximal part of spikelet 3–9-veined, at least in distal-most 1-veined, tip not notched ..... AMPHISCIRPUS

12' Ligule glabrous; stem, leaf generally with air cavities; stem rarely wiry; flower bracts dull, 1-veined, tip generally notched ..... SCHOENOPLECTUS

7' Flower stems with cauline leaves >= 1 (see also Schoenoplectus saximontanus)

13. Inflorescences generally > 1, terminal and generally >= 1 axillary

14. Flowers 10–50 per spikelet ..... SCIRPUS (2)

14' Flowers < 6 per spikelet

15. Stem 5–10 mm diam; leaf blades 5–10 mm wide, margins saw-toothed ..... CLADIUM

15' Stem <= 2 mm diam; leaf blades 0.5–5 mm wide, margins generally scabrous ..... RHYNCHOSPORA

13' Inflorescence 1, terminal

16. Leaf sheath tip margins scabrous or ciliate; stem, leaf blades glabrous or generally ± scabrous or puberulent

17. Leaf sheath tip ciliate, hairs >> 1 mm, soft ..... BULBOSTYLIS

17' Leaf sheath tip scabrous, hairs << 1 mm, stiff ..... FIMBRISTYLIS

16' Leaf sheath tip margins glabrous; stem, leaf blades glabrous or on keels or angles scabrous

18. Stem cylindric; perianth bristles 10–25, smooth, >> fruit ..... ERIOPHORUM

18' Stem 3-angled; perianth bristles 3–6(12), barbed, < to > fruit

19. Flower bracts puberulent (glabrous in age), tip notched, generally with curved awn often broken off; tubers durable ..... BOLBOSCHOENUS

19' Flower bracts glabrous, tip entire or sharp-pointed, awn 0 or minute; tubers 0

20. Inflorescence congested, head-like; perianth bristles > fruit ..... CALLISCIRPUS

20' Inflorescence openly branched with head-like clusters at branch tips; perianth bristles <= fruit ..... SCIRPUS (2)

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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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