OregonFlora: Eleocharis bolanderi

	Eleocharis bolanderi
	Bolander's spikerush
Habit	Plants perennial, densely cespitose; rhizomes caudex-like, mostly hidden by culms and roots, short, 1.5–3 mm thick, internodes very short.
Culms	subterete, 10–30 cm × 0.3–0.5 mm.
Spikes	ovoid, 3–8 × 2–3 mm; proximal scale clasping; entire, subproximal scale with flower; floral scales 8–30, 4–5 per mm of rachilla, 2–3 × 1.5 mm; apex entire; acute, often keeled in distal part of spike.
Flowers	perianth bristles 3–6, often unequal; from rudimentary to 50% of achene length; anthers 0.9–1.4 mm; stigmas 3.
Achenes	slightly to greatly compressed-trigonous, rarely thickly lenticular, 0.9–1.2 × 0.65–0.8 mm.
Distal leaf sheaths	persistent, not splitting; apex obtuse, rarely hardened, lacking a tooth.
Tubercles	flat to shallowly pyramidal; lower than wide, 0.1–0.3 × 0.4–0.65 mm.

	Eleocharis bolanderi
Distribution	[WildflowerSearch map] [BONAP county map]
Discussion	Shallow, rocky, ephemeral streams. 1100–2100 m. BR, BW, Owy. CA, NV, ID; east to CO. Native. Eleocharis bolanderi is easily recognized in summer when it forms masses of dry, brown, dormant and apparently dead culms in dry stream beds. It is easily pulled up to expose its cespitose habit. The virtually flat tubercles are particularly distinctive.
Source	Flora of Oregon, volume 1, page 240 Barbara Wilson, Richard Brainerd, Nick Otting
Sibling taxa	E. acicularis, E. bella, 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: 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 bolanderi

Bolander's spikerush

Habit

Plants perennial, densely cespitose; rhizomes caudex-like, mostly hidden by culms and roots, short, 1.5–3 mm thick, internodes very short.

Culms

subterete, 10–30 cm × 0.3–0.5 mm.

Spikes

ovoid, 3–8 × 2–3 mm;

proximal scale clasping; entire, subproximal scale with flower; floral scales 8–30, 4–5 per mm of rachilla, 2–3 × 1.5 mm;

apex entire; acute, often keeled in distal part of spike.

Flowers

perianth bristles 3–6, often unequal; from rudimentary to 50% of achene length;

anthers 0.9–1.4 mm;

stigmas 3.

Achenes

slightly to greatly compressed-trigonous, rarely thickly lenticular, 0.9–1.2 × 0.65–0.8 mm.

Distal leaf sheaths

persistent, not splitting;

apex obtuse, rarely hardened, lacking a tooth.

Tubercles

flat to shallowly pyramidal; lower than wide, 0.1–0.3 × 0.4–0.65 mm.

Eleocharis bolanderi

Distribution

[WildflowerSearch map]

[BONAP county map]

Discussion

Shallow, rocky, ephemeral streams. 1100–2100 m. BR, BW, Owy. CA, NV, ID; east to CO. Native.

Eleocharis bolanderi is easily recognized in summer when it forms masses of dry, brown, dormant and apparently dead culms in dry stream beds. It is easily pulled up to expose its cespitose habit. The virtually flat tubercles are particularly distinctive.

Source

Flora of Oregon, volume 1, page 240
Barbara Wilson, Richard Brainerd, Nick Otting

Sibling taxa