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Eleocharis acicularis
NEEDLE SPIKERUSH

Higher Taxonomy
Family: CyperaceaeView DescriptionDichotomous Key

Common Name: SEDGE FAMILY
Habit: Annual, perennial herb, often rhizomed or stoloned, often of wet open places; roots fibrous; monoecious, dioecious, or flowers bisexual. Stem: generally 3-sided, generally solid. Leaf: generally 3-ranked; base sheathing, sheath generally closed, ligule generally 0; blade (0 or) linear, parallel-veined. Inflorescence: spikelets generally arranged in head-, spike-, raceme-, or panicle-like inflorescences; flower generally sessile in axil of flower bract, enclosed in a sac-like structure (perigynium) or generally not. Flower: unisexual or bisexual, small, generally wind-pollinated; perianth 0 or generally bristle like; stamens generally 3, anthers attached at base, 4 chambered; ovary superior, chamber 1, ovule 1, style 2--3-branched. Fruit: achene, 2--3 sided.
Genera In Family: +- 100 genera, 5000 species: especially temperate. Note: Difficult; taxa differ in technical characters of inflorescence, fruit. In Carex and Kobresia, what appear to be individual pistillate flowers in fact are highly reduced inflorescences (whether or not the same applies to staminate flowers is still under debate). In some other works (e.g., FNANM) these are called spikelets, and they are treated as being arranged in spikes. Here and in TJM (1993), what appear to be individual pistillate flowers are called pistillate flowers in Carex (and they are treated as being arranged in spikelets), but spikelets in Kobresia (and they are treated as being arranged into spikes). Though internally inconsistent, the approach here is consistent with traditional usage, and reflects a preference for character states that may be determined in the field. Molecular, morphological, and embryological evidence indicates that Eriophorum crinigerum is to be segregated to a new genus, as Calliscirpus criniger (A. Gray) C.N. Gilmour et al., along with a second, newly described species, Calliscirpus brachythrix C.N. Gilmour et al. (Gilmour et al. 2013); key to genera modified by Peter W. Ball to include Calliscirpus.
eFlora Treatment Author: S. Galen Smith, except as noted
Scientific Editor: S. Galen Smith, Thomas J. Rosatti, Bruce G. Baldwin.
Genus: EleocharisView DescriptionDichotomous Key

Common Name: SPIKERUSH
Habit: 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.
Species In Genus: +- 200 species: tropics to boreal. Etymology: (Greek heleios, dwelling in a marsh, and Charis, grace) Note: Eleocharis lanceolata Fernald, Eleocharis equisetoides Torr. not in California.

Eleocharis acicularis (L.) Roem. & Schult.
NATIVE
Habit: Perennial herb 1--60 cm, often forming mats; rhizome weak, to 0.5 mm diam. Stem: 0.2--0.5(7) mm diam, subcylindric, often 3--12- angled or -ridged. Leaf: distal sheath delicate, often disintegrating, tip inflated or not. Inflorescence: spikelet 2--8 mm, 1--2 mm wide, often 0 on submersed plants; flower bracts to 25, 1.5--2.5(3.5) mm, tip blunt to acute, not recurved, basal with flower. Flower: anthers 0.7--1.5 mm; stigmas 3. Fruit: 0.7--1 mm, 0.4--0.6 mm wide, 3-sided to +- round in ×-section, often +- white, longitudinal ridges +- 8--12, crossbars 30--60 per ridge; perianth bristles 0 (2--4, <= fruit).
Note: Deeply submersed variants (Eleocharis acicularis var. submersa (Nilsson) Svenson), which often form large vegetative mats and often long thread-like stems without spikelets, may closely resemble Schoenoplectus subterminalis. Varieties often not identifiable.
eFlora Treatment Author: S. Galen Smith
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Citation for this treatment: S. Galen Smith 2016. Eleocharis acicularis, in Jepson Flora Project (eds.) Jepson eFlora, http://ucjeps.berkeley.edu/cgi-bin/get_IJM.pl?tid=23926, accessed on December 09, 2016.

Citation for the whole project: Jepson Flora Project (eds.) 2016. Jepson eFlora, http://ucjeps.berkeley.edu/IJM.html, accessed on December 09, 2016.


Eleocharis acicularis var. acicularis
click for enlargement
© 2015 Keir Morse
Eleocharis acicularis var. acicularis
click for enlargement
© 2003 Steve Matson
Eleocharis acicularis var. acicularis
click for enlargement
© 2003 Steve Matson
Eleocharis acicularis var. acicularis
click for enlargement
© 2003 Steve Matson
Eleocharis acicularis var. acicularis
click for enlargement
© 2015 Keir Morse
Eleocharis acicularis var. acicularis
click for enlargement
© 2003 Steve Matson

More photos of Eleocharis acicularis in CalPhotos


Geographic subdivisions for Eleocharis acicularis:
Markers link to CCH specimen records. Yellow markers indicate records that may provide evidence for eFlora range revision or may have georeferencing or identification issues. Purple markers indicate specimens collected from a garden, greenhouse, or other non-wild location.
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map of distribution 1
(Note: any qualifiers in the taxon distribution description, such as 'northern', 'southern', 'adjacent' etc., are not reflected in the map above, and in some cases indication of a taxon in a subdivision is based on a single collection or author-verified occurence).

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Data provided by the participants of the Consortium of California Herbaria.
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Duplicates counted once; synonyms included.
Species do not include records of infraspecific taxa.
Blue line denotes eFlora flowering time.