Eleocharis

Scientific name

Eleocharis R. Br.

Common names

spikerush

Family

Cyperaceae

Similar genera

Equisetum, Isoetes, Isolepis, Juncus, Schoenoplectus, Triglochin

Native distribution

cosmopolitancosmopolitan:
(adj) essentially worldwide in distribution

Species cultivated

(additional cultivated varieties traded)

Eleocharis acicularis (L.) Roem. & Schult.

E. caespitosissima Baker

E. dulcis (Burm.f.) Trin. ex Hensch. [also offered under the synonym E. tuberosa Schult.]

E. geniculata (L.) Roem. & Schult.

E. montevidensis Kunth

E. obtusa (Willd.) Schult.

E. palustris (L.) Roem. & Schult.

E. parvula (Roem. & Schult.) Link ex Bluff, Nees & Schauer

E. quadrangulata (Michx.) Roem. & Schult.

E. vivipara Link

Adventive distribution

Eleocharis acicularis, E. dulcis, and E. palustris are so widely distributed around the world that it is difficult to determine in what parts of this range they are native.

Weed status

Eleocharis acicularis, E. dulcis and E. palustris are considered serious weeds of rice fields and waterways in numerous countries around the world.

Habit

submersedsubmersed:
see submerged
, emergentemergent:
(adj) (syn. emersed) with parts raised out of the water; extending up out of the water
, rhizomatousrhizomatous:
(adj) possessing rhizomes

Brief description

Annual or perennialperennial:
(adj) (of a plant) having a life cycle of more than two years
sedge. Rhizomerhizome:
(n) an underground stem, usually growing horizontally, from which both roots and shoots emerge directly; the thick, above-ground stem of ferns
slender, extending horizontally beneath substrate, producing erect stems at regularregular:
(adj) uniform in shape or structure; radially symmetrical and parts similar in size and arrangement
intervals. Roots sometimes bearing storage tubers. Stem typically cylindricalcylindrical:
(adj) forming a nearly true cylinder
or angled, often jointed (septateseptate:
(adj) divided or partitioned by cross-walls
). Leaves reduced to membranous basalbasal:
(adj) at or pertaining to the base, or point of attachment
leaf sheaths. Inflorescenceinflorescence:
(n) the arrangement of flowers on the floral axis
a solitary, terminalterminal:
(adj) at the apex
spikeletspikelet:
(n) a small spike; basic unit of the grass and sedge inflorescence, commonly consisting of one to many florets (small flowers) subtended by bracts
; spikelets few- to many-flowered, not subtended by bracts; outer bracts spirally arranged. Flowers bisexualbisexual:
(adj) having both male and female sexual reproductive structures on one individual or in one flower
; perianthperianth:
(n) collective term for the calyx and corolla of a flower; also used for floral whorl(s) in which the calyx and corolla cannot be resolved; any of the leaves or bracts surrounding the sex organs of bryophytes
reduced to bristles with 2-3 stamens. Dispersal by seeds or rhizomerhizome:
(n) an underground stem, usually growing horizontally, from which both roots and shoots emerge directly; the thick, above-ground stem of ferns
fragments.

Natural habitat

common in shallow, sandy waters of all water bodies; also on wet ground

Additional comments

A very large and morphologically diverse genus of over 180 species worldwide. A few species are used in aquaria or ponds. Eleocharis dulcis (‘water chestnut’) is grown commercially, and the root tubers serve as a food source.