OregonFlora: Eleocharis erythropoda vs. Eleocharis bernardina

	Eleocharis erythropoda	Eleocharis bernardina
	bald spikerush
Habit	Plants perennial, mat-forming; rhizomes evident, long, 0.5–1.5 mm thick, soft to firm, cortex often breaking loose, longer internodes 5–30 mm.
Culms	terete, 8–80 cm × 0.3–1.4 mm.
Spikes	ovoid to lanceoloid or nearly cylindric, 3–18 × 2–3(4) mm; proximal scale clasping all or nearly all of culm, subproximal scale with flower; floral scales 15–50, 4–5 per mm of rachilla, 2–3.5 × 1.5–1.7 mm; in proximal part of spike apex rounded; in distal part apex entire; acute.
Flowers	perianth bristles 4 or absent, usually equal, equaling achene to slightly exceeding tubercle; anthers 1–1.8 mm; stigmas 2.
Achenes	biconvex, 0.9–1.6 × 0.7–1.2 mm
Distal leaf sheaths	persistent; apex broadly obtuse to subacute; tooth sometimes present; to 0.1 mm.
Tubercles	pyramidal; much higher than wide to lower than wide, 0.35–0.65 × 0.2–0.6 mm.
2n	=16, 18, 19, 20.

	Eleocharis erythropoda	Eleocharis bernardina
Distribution	[WildflowerSearch map]
Discussion	Marshes, wet meadows, fens, disturbed wetlands. 500–1500 m. BR, Owy. ID, WA; north to AK, east to New Brunswick and NC, southeast to AZ and MS. Native. Eleocharis erythropoda is the most delicate member of the E. palustris complex. Its proximal scales consistently clasp the entire culm, and its subproximal scales consistently subtend flowers. Intermediates between E. erythropoda and E. macrostachya may be more common in Oregon than pure E. erythropoda.
Source	Flora of Oregon, volume 1, page 241 Barbara Wilson, Richard Brainerd, Nick Otting
Sibling taxa	E. acicularis, E. bella, E. bolanderi, E. decumbens, E. engelmannii, E. macrostachya, E. obtusa, E. ovata, E. palustris, E. parishii, E. parvula, E. quadrangulata, E. quinqueflora, E. rostellata, E. suksdorfiana	E. acicularis, E. bella, E. bolanderi, E. decumbens, E. engelmannii, E. erythropoda, E. macrostachya, E. obtusa, E. ovata, E. palustris, E. parishii, E. parvula, E. quadrangulata, E. quinqueflora, E. rostellata, E. suksdorfiana
Web links	Local floras: BC, OR, WA Local Web sites: 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: CA 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 erythropoda

Eleocharis bernardina

bald spikerush

Habit

Plants perennial, mat-forming; rhizomes evident, long, 0.5–1.5 mm thick, soft to firm, cortex often breaking loose, longer internodes 5–30 mm.

Culms

terete, 8–80 cm × 0.3–1.4 mm.

Spikes

ovoid to lanceoloid or nearly cylindric, 3–18 × 2–3(4) mm;

proximal scale clasping all or nearly all of culm, subproximal scale with flower; floral scales 15–50, 4–5 per mm of rachilla, 2–3.5 × 1.5–1.7 mm; in proximal part of spike apex rounded; in distal part apex entire; acute.

Flowers

perianth bristles 4 or absent, usually equal, equaling achene to slightly exceeding tubercle;

anthers 1–1.8 mm;

stigmas 2.

Achenes

biconvex, 0.9–1.6 × 0.7–1.2 mm

Distal leaf sheaths

persistent;

apex broadly obtuse to subacute; tooth sometimes present; to 0.1 mm.

Tubercles

pyramidal; much higher than wide to lower than wide, 0.35–0.65 × 0.2–0.6 mm.

=16, 18, 19, 20.

Eleocharis erythropoda

Eleocharis bernardina

Distribution

[WildflowerSearch map]

Discussion

Marshes, wet meadows, fens, disturbed wetlands. 500–1500 m. BR, Owy. ID, WA; north to AK, east to New Brunswick and NC, southeast to AZ and MS. Native.

Eleocharis erythropoda is the most delicate member of the E. palustris complex. Its proximal scales consistently clasp the entire culm, and its subproximal scales consistently subtend flowers. Intermediates between E. erythropoda and E. macrostachya may be more common in Oregon than pure E. erythropoda.

Source

Flora of Oregon, volume 1, page 241
Barbara Wilson, Richard Brainerd, Nick Otting

Sibling taxa