The green links below add additional plants to the comparison table. Blue links lead to other Web sites.
enable glossary links

Chambers' bluegrass

Habit Plants perennial, dioecious or gynodioecious, 10–50 cm long; loosely cespitose or with solitary shoots, short-rhizomatous.
Culms

nodes terete, 0–1 exserted.

Basal branching

intra- and extravaginal or mostly intravaginal.

Leaves

sheaths closed 33–88% of their length, bases of basal sheaths glabrous;

collars smooth, glabrous;

ligules 0.5–2(2.5) mm;

cauline blades flat or folded, 2–5 mm wide; smooth or upper surface sparsely scabrous, mainly over the veins;

blades gradually reduced up the culm; uppermost blade 0.7–6 cm.

Inflorescences

erect, lanceoloid to ovoid, tightly to loosely contracted, 2–9 cm;

spikelets 15–30;

proximal internodes less than 2 cm;

branches erect to ascending to slightly spreading, 1–2 per node, 0.9–3.2 cm, with 1–4 spikelets.

Spikelets

to 3 times as long as wide, 6–12 mm;

florets 2–7;

rachilla internodes 0.8–1.5 mm long.

Glumes

60–80% as long as adjacent lemmas;

lower glumes 3-veined.

Calluses

of at least some lower florets with sparse cobwebby hairs, rarely all florets glabrous;

hairs 1–2 mm.

Lemmas

lanceolate, 5–7 mm, distinctly keeled; smooth or sparsely finely scabrous, glabrous throughout or keels and marginal veins sparsely soft-puberulent over the proximal 20%; area between the veins glabrous, 5–7-veined;

tips acute.

Anthers

vestigial and 0.1–0.2 mm, aborted late in development, or 1.8–3.7 mm.

Poa cuspidata

Poa chambersii

Distribution
[WildflowerSearch map]
[BONAP county map]
[BONAP county map]
Discussion

Openings in upland forest and snowmelt pockets in alpine areas. 1700–2800m. BR, Casc. Native.

Although some plants may be pistillate, populations always include individuals with functional anthers. Poa chambersii is similar to P. wheeleri and P. cusickii ssp. purpurescens, but the latter have denser inflorescences and only pistillate spikelets. Poa chambersii populations in the Cascades are dioecious; those on Steens Mountain are gynodioecious and will be described as a new species in the future.

Source Flora of Oregon, volume 1, page 454
Rob Soreng, Barbara Wilson, Richard Brainerd, Nick Otting
Sibling taxa
P. alpina, P. annua, P. bolanderi, P. bulbosa, P. chambersii, P. compressa, P. confinis, P. cusickii, P. fendleriana, P. glauca, P. howellii, P. iconia, P. infirma, P. laxiflora, P. leibergii, P. leptocoma, P. lettermanii, P. macrantha, P. mansfieldii, P. marcida, P. nemoralis, P. nervosa, P. palustris, P. piperi, P. pratensis, P. pringlei, P. reflexa, P. rhizomata, P. secunda, P. stenantha, P. suksdorfii, P. trivialis, P. unilateralis, P. wallowensis, P. wheeleri
P. alpina, P. annua, P. bolanderi, P. bulbosa, P. compressa, P. confinis, P. cusickii, P. fendleriana, P. glauca, P. howellii, P. iconia, P. infirma, P. laxiflora, P. leibergii, P. leptocoma, P. lettermanii, P. macrantha, P. mansfieldii, P. marcida, P. nemoralis, P. nervosa, P. palustris, P. piperi, P. pratensis, P. pringlei, P. reflexa, P. rhizomata, P. secunda, P. stenantha, P. suksdorfii, P. trivialis, P. unilateralis, P. wallowensis, P. wheeleri
Web links