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Key to families | Table of families and genera

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.

 

ELEOCHARIS SPIKERUSH
Annual, perennial herb, generally forming mats, glabrous, internal air cavities evident; caudex generally 0; rhizomes generally evident, long, scaly, bulb or tuber at tip generally 0. Stem: simple, generally erect, smooth, generally not hollow; tip generally not rooting. Leaf: 2, basal, blades 0 or tooth-like, <= 1 mm. Inflorescence: inflorescence bracts 0; spikelet terminal, 1, generally ovate, not ± flat [(± flat)], generally not forming plantlets, flowers 3–100+; flower bracts spiraled [(2-ranked)], each with 1 flower in axil, generally ovate, generally brown, generally membranous, smooth, tip generally acute to obtuse, notch 0; basal flower bract generally encircling stem, generally < 1/2 spikelet, flower generally 0. Flower: bisexual; perianth parts reduced to bristles, 0–8, generally ± <= fruit, barbs generally recurved; stamens generally 3; style 1, thread-like, base enlarged, generally persistent on fruit as tubercle. Fruit: generally obovate, generally brown; tubercle (0 or) generally distinct, generally pyramidal.
Wetland obligates.
± 200 species: tropics to boreal. (Greek: marsh-dwelling grace) [Smith et al. 2002 FNANM 23:60–120] Eleocharis lanceolata Fernald, Eleocharis equisetoides Torr. not in California.
Unabridged etymology: (Greek heleios, dwelling in a marsh, and Charis, grace)

Key to 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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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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