Burke: Eleocharis engelmannii vs. Eleocharis palustris

	Eleocharis engelmannii	Eleocharis palustris
	Engelman spikerush	common spikerush
Habit	Tufted annual, 0.5-5 dm. tall, the culms 0.5-2 mm. thick, with many ribs.	Herbaceous, rhizomatous perennial, the culms scattered or in clumps along the rhizome, slender to stout, 1-10 dm. tall.
Leaves	Leaves all basal and reduced to sheaths.	Leaf sheaths red or black at base, green or red towards tip, not inflated or callose, membranous to papery, tips broadly obtuse to acute, tooth lacking.
Flowers	Spikelet terminal and solitary, 5-13 mm. long, ovoid, many-flowered, usually over 40; scales spirally arranged, 1.7-2.5 mm. long, purplish or brownish, with greenish mid-strip and paler, translucent margins, the lowest one sometimes empty; perianth bristles 6-7, brownish, about equal to the achene, or wanting; stamens 3; style usually bifid, thickened at the base.	Spikelet terminal and solitary, 5-23 mm. long, lanceolate in outline, brown or chestnut-colored; scales of the spikelet spirally arranged 2-4.5 mm. long, with 1 or 2 empty scales at the base of the spikelet, the lower one encircling the culm; perianth bristles usually 4, retrorsely barbed; stamens 2; styles bifid, thickened at the base.
Fruits	Achenes lenticular, 1.0-1.5 mm. long, including the flattened tubercle, which is appressed to the summit of the brown, smooth and shining body of the achene.	Achenes lenticular, yellow to brown, 1.5-2.5 mm. long, including a tubercle 0.4-0.7 mm. long.

	Eleocharis engelmannii	Eleocharis palustris
Flowering time	June-September	May-August
Habitat	Marshes and other wet places, from sea level to moderate elevations in the mountains.	Wet places from sea level to moderate elevations in the mountains; tolerant of alkali.
Distribution	Occurring on both sides of the Cascades crest in Washington; Alaska to California, east across most of North America to the Atlantic Coast. [WildflowerSearch map] [BONAP county map]	Widely distributed on both sides of the Cascades crest in Washington; Alaska to California, east across North America to the Atlantic Coast. [WildflowerSearch map] [BONAP county map]
Origin	Native	Native
Conservation status	Not of concern	Not of concern
Sibling taxa	E. acicularis, E. bella, E. bolanderi, E. coloradoensis, E. erythropoda, E. geniculata, E. macrostachya, E. mamillata, E. obtusa, E. ovata, E. palustris, E. parvula, E. quinqueflora, E. rostellata, E. suksdorfiana, E. uniglumis	E. acicularis, E. bella, E. bolanderi, E. coloradoensis, E. engelmannii, E. erythropoda, E. geniculata, E. macrostachya, E. mamillata, E. obtusa, E. ovata, E. parvula, E. quinqueflora, E. rostellata, E. suksdorfiana, E. uniglumis
Web links	Local floras: BC, CA, OR, WA Local Web sites: CalFlora, CalPhotos, Flora NW, PNW Herbaria WildflowerSearch iNaturalist (observations) USDA Plants Database LBJ Wildflower Center SEINet Plants of the World Online Encyclopedia of Life Wikipedia Google Image Search	Local floras: BC, CA, OR, WA Local Web sites: CalFlora, CalPhotos, Flora NW, PNW Herbaria WildflowerSearch iNaturalist (observations) USDA Plants Database LBJ Wildflower Center SEINet Plants of the World Online Encyclopedia of Life Wikipedia Google Image Search

Eleocharis engelmannii

Eleocharis palustris

Engelman spikerush

common spikerush

Habit

Tufted annual, 0.5-5 dm. tall, the culms 0.5-2 mm. thick, with many ribs.

Herbaceous, rhizomatous perennial, the culms scattered or in clumps along the rhizome, slender to stout, 1-10 dm. tall.

Leaves

Leaves all basal and reduced to sheaths.

Leaf sheaths red or black at base, green or red towards tip, not inflated or callose, membranous to papery, tips broadly obtuse to acute, tooth lacking.

Flowers

Spikelet terminal and solitary, 5-13 mm. long, ovoid, many-flowered, usually over 40;

scales spirally arranged, 1.7-2.5 mm. long, purplish or brownish, with greenish mid-strip and paler, translucent margins, the lowest one sometimes empty;

perianth bristles 6-7, brownish, about equal to the achene, or wanting;

stamens 3;

style usually bifid, thickened at the base.

Spikelet terminal and solitary, 5-23 mm. long, lanceolate in outline, brown or chestnut-colored;

scales of the spikelet spirally arranged 2-4.5 mm. long, with 1 or 2 empty scales at the base of the spikelet, the lower one encircling the culm;

perianth bristles usually 4, retrorsely barbed;

stamens 2;

styles bifid, thickened at the base.

Fruits

Achenes lenticular, 1.0-1.5 mm. long, including the flattened tubercle, which is appressed to the summit of the brown, smooth and shining body of the achene.

Achenes lenticular, yellow to brown, 1.5-2.5 mm. long, including a tubercle 0.4-0.7 mm. long.