Jepson eFlora
Key to families | Table of families and genera

Key to Eleocharis

View taxon page for Eleocharis

1. Stem 4-angled, 1–5.4 mm diam ..... E. quadrangulata

1' Stem rarely 4-angled, if so then < 1 mm diam

2. Rhizomes, caudices 0; annual (perennial herb)

3. Distal leaf sheath delicate, often disintegrating; basal flower bract with a flower; stigmas 3; fruit with ± 6–10 longitudinal ridges, many fine transverse bars; plants 1–7 cm ..... E. bella (2)

3' Distal leaf sheath firm, persistent; basal flower bract with a flower or not; stigmas 2–3; fruit smooth; plants 1–50 cm

4. Fruit black (brown when immature); tubercle not completely adherent to fruit, not flat

5. Fruit 0.3–0.5 mm; perianth bristles generally ± white; flower bracts membranous ..... E. atropurpurea

5' Fruit 0.5–1.1 mm; perianth bristles generally red-brown; flower bracts membranous to papery ..... E. geniculata

4' Fruit brown; tubercle completely adherent to fruit, flat

6. Tubercle <= 1/4 fruit; perianth bristles 0 or 5–8, vestigial, << fruit, or ± = fruit ..... E. engelmannii

7. Perianth bristles 0 or vestigial, << fruit ..... var. detonsa

7' Perianth bristles ± = fruit ..... var. engelmannii

6' Tubercle >= 1/3 fruit; perianth bristles (0 or) 5–7, to generally much exceeding tubercle

8. Tubercle 0.5–0.8 mm wide, 2/3–9/10 as wide as fruit ..... E. obtusa

8' Tubercle 0.3–0.5 mm wide, 1/2–3/4 as wide as fruit ..... E. ovata

2' Rhizomes or caudices present; perennial herb (annual)

9. Distal leaf sheath delicately membranous, often disintegrating; stem 0.2–1 mm diam

10. Basal flower bract without a flower; fruit with 2–3 longitudinal angles, 0 transverse bars

11. Fruit 2-sided; distal leaf sheath tip much inflated, generally wrinkled; tubercle distinct from fruit; rhizome tip without tuber ..... E. flavescens var. flavescens

11' Fruit (2)3-sided; distal leaf sheath not inflated or wrinkled; tubercle often merging with fruit or vestigial; rhizome tip often with tuber

12. Perianth bristles 0 or vestigial or ± 1/2 fruit; fruit finely roughened; rhizome tip tubers 0 or wide-oblong to spheric, not curved; generally inland ..... E. coloradoensis

12' Perianth bristles (vestigial or) generally = fruit to ± exceeding tubercle; fruit smooth; rhizome tip tubers 0 or oblong, often curved; generally coastal ..... E. parvula

10' Basal flower bract with a flower; fruit with 6–12 longitudinal ridges, many fine transverse bars

13. Flower bract 1–1.5 mm, tip narrow-acute to acuminate, ± recurved; anthers 0.3–0.5 mm ..... E. bella (2)

13' Flower bract 1.5–2.5(3.5) mm, tip blunt to acute, not recurved; anthers 0.3–1.5 mm

14. Anthers <= 0.5 mm; stem very spongy, without angles or ridges, 0.4–1 mm diam ..... E. radicans

14' Anthers 0.7–1.5 mm; stem not very spongy, often with 3–12 angles or ridges, 0.2–0.5(0.7) mm diam ..... E. acicularis

15. Fruit 2 × longer than wide; stem often 3–4-angled, base not corm-like ..... var. acicularis

15' Fruit < 2 × longer than wide; stem often 5–12-ridged, base corm-like or not

16. Stem to 60 cm, base not corm-like ..... var. gracilescens

16' Stem to 6 cm, base corm-like ..... var. occidentalis

9' Distal leaf sheath firmly membranous to papery, persistent; stem 0.2–4 mm diam

17. Distal leaf sheath tips some or all with tooth-like projection to 1 mm

18. Stigmas 2; fruit 2-sided; basal flower bracts not completely clasping stem and/or at least some spikelets with next-to-basal bract without flower ..... E. macrostachya (2)

18' Stigmas 3; fruit 3-sided; basal flower bracts completely clasping stem, next-to-basal bract with flower

19. Flower bracts 5–10 per 1 mm of spikelet (spikelet 4–12 mm, flower bracts 30–100), tips wide-rounded, often transversely wrinkled and recurved ..... E. montevidensis (2)

19' Flower bracts 3–4 per 1 mm of spikelet (spikelet 3–20 mm, flower bracts 15–40), tips rounded to acute, not transversely wrinkled, not recurved ..... E. parishii (2)

17' Distal leaf sheath tips without tooth-like projection

20. Stigmas 2; fruit 2-sided; basal flower bract without flower

21. Basal flower bracts, or at least some, clasping >= 3/4 of stem, next-to-basal with a flower or not ..... E. macrostachya (2)

21' Basal flower bracts clasping 2/3 to 3/4 of stem, next-to-basal without a flower ..... E. palustris

20' Stigmas (2)3; fruit (2)3-sided; basal flower bract with or without flower

22. Rhizome mostly hidden by stems and/or >= 3 mm diam, often caudex-like, tip without enlarged bud or bulb

23. Stem sharp-4-angled; spikelets often forming plantlets ..... E. pachycarpa

23' Stem not sharp-4-angled; spikelets not forming plantlets (stem tips often rooting in Eleocharis rostellata)

24. Stems ± flat, some elongating and arching, tips often rooting; flower bracts 3.5–6 mm; fruit 1.5–2.5 mm ..... E. rostellata

24' Stem subcylindric, not elongating and arching, tips not rooting; flower bracts 2–3.5 mm; fruit 0.8–1.2 mm

25. Rhizome 1.5–3 mm diam, hidden by stems; flower bracts dark brown; stem 0.3–0.5 mm diam ..... E. bolanderi

25' Rhizome 3–5 mm diam, mostly not hidden by stems; flower bracts medium brown; stem 0.3–2 mm diam ..... E. decumbens

22' Rhizome not hidden by stems, <= 2 mm diam, tip with enlarged bud or bulb

26. Flower bracts 1.5–2.5 mm; rhizome tough, tip without enlarged bud or bulb; tubercle distinct from fruit; basal flower bract < 1/2 spikelet

27. Flower bract tips in proximal 1/2 of spikelet wide-rounded, generally transversely wrinkled and recurved; fruit fine-wrinkled at 10–30× ..... E. montevidensis (2)

27' Flower bract tips in proximal 1/2 of spikelet rounded to acute, generally not transversely wrinkled and recurved; fruit smooth, wrinkled, or lattice-like at 10–30× ..... E. parishii (2)

27A. Spikelets narrow-lanceolate to cylindric; fruit brown, smooth or lattice-like at 10–30×; rhizomes with longer internodes 5–30 mm ..... E. parishii

27A' Spikelets ovate; fruit yellow, brown, green, or yellow-green, fine-wrinkled, generally lattice-like at 10–20×; rhizomes with longer internodes 2–10 mm ..... [E. tenuis var. tenuis]

26' Flower bracts 2.5–6 mm; rhizome weak, tip often with enlarged bud or bulb; tubercle often ± not distinct from fruit; basal flower bract generally >= 1/2 spikelet

28. St-tuft base generally swollen, often with bulbs; rhizome tip often with bulb; caudex generally 0 ..... E. quinqueflora

28' St-tuft base not swollen, without bulbs; rhizome tip without bulb; caudex present

29. Stem 1.5–2.5 mm wide, flat, spirally twisted; n High Sierra Nevada ..... E. torticulmis

29' Stem 0.5–1.2 mm wide, cylindric to ± flat, not spirally twisted; Northwestern California, High Cascade Range, Sierra Nevada, San Francisco Bay Area, Transverse Ranges, Desert Mountains

30. Stem strongly arched; perianth bristles 4–7, some < 1/2 fruit, others equaling or exceeding tubercle; Transverse Ranges ..... E. bernardina

30' Stem generally straight; perianth bristles 6, longest = fruit to exceeding tubercle; Northwestern California, High Cascade Range, Sierra Nevada, San Francisco Bay Area, Transverse Ranges, Desert Mountains ..... E. suksdorfiana

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