''Eleocharis macrostachya'' is a species of spikesedge known by the common name pale spikerush. It is widely distributed in

North America North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and the Car ...

and occurs in parts of

South America South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere at the northern tip of the continent. It can also be described as the southe ...

.Kew World Checklist of Selected Plant Families
/ref> It is a plant of varied moist habitats, including freshwater lakes and brackish marshes and ponds, ditches,

vernal pool Vernal pools, also called vernal ponds or ephemeral pools, are seasonal pools of water that provide habitat for distinctive plants and animals. They are considered to be a distinctive type of wetland usually devoid of fish, and thus allow the safe ...

s, and

wet meadow A wet meadow is a type of wetland with soils that are saturated for part or all of the growing season. Debate exists whether a wet meadow is a type of marsh or a completely separate type of wetland. Wet prairies and wet savannas are hydrologically ...

Description

''Eleocharis macrostachya'' is a

rhizomatous In botany and dendrology, a rhizome (; , ) is a modified subterranean plant stem that sends out roots and shoots from its nodes. Rhizomes are also called creeping rootstalks or just rootstalks. Rhizomes develop from axillary buds and grow hori ...

perennial generally reaching heights between one half and one meter. It has bright green erect stems and straw-colored basal leaves. The top of each stem is occupied by a narrow, lance-shaped or cylindrical

inflorescence An inflorescence is a group or cluster of flowers arranged on a stem that is composed of a main branch or a complicated arrangement of branches. Morphologically, it is the modified part of the shoot of seed plants where flowers are formed o ...

. The

spikelet A spikelet, in botany, describes the typical arrangement of the flowers of grasses, sedges and some other Monocots. Each spikelet has one or more florets. The spikelets are further grouped into panicles or spikes. The part of the spikelet that ...

is one or two centimeters long and has at least ten flowers, each covered with a purplish-brown

bract In botany, a bract is a modified or specialized leaf, especially one associated with a reproductive structure such as a flower, inflorescence axis or cone scale. Bracts are usually different from foliage leaves. They may be smaller, larger, or of ...

. The fruit is a yellow or yellow-brown

achene An achene (; ), also sometimes called akene and occasionally achenium or achenocarp, is a type of simple dry fruit produced by many species of flowering plants. Achenes are monocarpellate (formed from one carpel) and indehiscent (they do not ope ...

with a whitish cone-shaped tubercle on one end, measuring one or two millimeters long.

Use in phytoremediation efforts

''E. macrostachya'' has been studied as part of wetland restoration, as well as the removal of

arsenic in groundwater Arsenic contamination of groundwater is a form of groundwater pollution which is often due to naturally occurring high concentrations of arsenic in deeper levels of groundwater. It is a high-profile problem due to the use of deep tube wells for ...

via

rhizofiltration Rhizofiltration is a form of phytoremediation that involves filtering contaminated groundwater, surface water and wastewater through a mass of roots to remove toxic substances or excess nutrients. Overview Rhizofiltration is a type of phytoremedia ...

as part of

phytoremediation Phytoremediation technologies use living plants to clean up soil, air and water contaminated with hazardous contaminants. It is defined as "the use of green plants and the associated microorganisms, along with proper soil amendments and agronomi ...

. Wetlands have the capacity to remove many conventional contaminants from

wastewater Wastewater is water generated after the use of freshwater, raw water, drinking water or saline water in a variety of deliberate applications or processes. Another definition of wastewater is "Used water from any combination of domestic, industr ...

, even in highly saline water. Olmos-Marquez (2012) identified ''E. macrostachya'' as having the greatest arsenic retention in an experimental wetland, suggesting that it acts as a rhizofiltrator.

References

External links

Jepson Manual Treatment: ''Eleocharis macrostachya''USDA Plants Profile — ''Eleocharis macrostachya'' (pale spikerush)''Eleocharis macrostachya'' — U.C. Photo gallery
*C.Michael Hogan ed. 2010
''Eleocharis macrostachya''. Encyclopedia of Life
macrostachya Freshwater plants Brackish water plants Flora of North America Flora of Central America Flora of South America Flora of the United States Plants described in 1903 Phytoremediation plants {{Cyperaceae-stub