Poa paludigena |
Poa porsildii |
|
---|---|---|
bog bluegrass, eastern bog bluegrass |
Porsild's bluegrass |
|
Habit | Plants perennial; usually pale green; loosely tufted, slender, usually neither stoloniferous nor rhizomatous, occasionally with short, slender rhizomes. | Plants perennial; densely tufted, not stoloniferous, not rhizomatous. |
Culms | 10-55 cm, very slender, weak. |
(12)17-30(40) cm, erect or the bases decumbent, with (0)1(2) exserted nodes. |
Sheaths | closed for 1/4 - 3/5 their length, terete, smooth or sparsely scabrous, margins not ciliate; ligules 0.5-2 mm, smooth or sparsely scabrous, truncate; blades 0.8-2 mm wide, flat, thin, soft, apices narrowly prow-shaped. |
closed for 1/3 – 2/3 their length, terete, bases of basal sheaths glabrous; collars smooth, glabrous; ligules of cauline leaves 1-2 mm, smooth, apices truncate to obtuse, ligules of the innovation leaves shorter than 0.5 mm, scabrous, truncate; innovation blades not or indistinctly differentiated from the cauline blades, flat or weakly involute, adaxial surfaces sparsely to fairly densely finely scabrous between the veins; cauline blades 1-3 mm wide, folded, fairly thin to moderately thick, soft, abaxial surfaces smooth, apices narrowly prow-shaped. |
Basal branching | mostly extravaginal. |
intra-vaginal. |
Panicles | 3-8(12) cm, lax, open, sparse; nodes with 1-2(3) branches; branches (2)3-7 cm, spreading to reflexed, capillary, angled, angles scabrous. |
2-5(6) cm, erect or nodding, ovoid to pyramidal, slightly contracted or open, sparse, with fewer than 20 spikelets; nodes with 1-2 branches; branches 2-4 cm, ascending to widely spreading, occasionally reflexed, flexuous, lax, slender, terete, smooth or sparsely scabrous, with 1-3(4) spikelets. |
Spikelets | 3.2-5.2 mm, laterally compressed, broadly lanceolate to ovate; florets 2-3(5); rachilla internodes smooth, glabrous. |
4-7 mm, lengths to 3 times widths, broadly lanceolate to narrowly ovate, laterally compressed, not sexually dimorphic, often strongly anthocyanic; florets 3-4; rachilla internodes smooth, glabrous or sparsely puberulent. |
Glumes | narrowly lanceolate to lanceolate, thin, distinctly keeled, keels scabrous; lower glumes 1-3-veined; upper glumes shorter than or subequal to the adjacent lemmas; calluses sparsely webbed; lemmas 2.5-4 mm, lanceolate, green, distinctly keeled, keels and marginal veins short-villous, extending 2/3 – 4/5 the keel length, lateral veins fairly prominent, intercostal regions glabrous, apices obtuse to broadly acute, white, faintly bronze-colored or not; palea keels scabrous; anthers 0.2-0.8 mm. |
thin, somewhat lustrous, distinctly keeled, keels smooth; lower glumes 3-veined, distinctly shorter than the lowest lemmas; calluses glabrous; lemmas 4-6 mm, lanceolate, distinctly keeled, thinly membranous, sparsely to moderately densely and finely scabrous, usually glabrous, rarely sparsely softly puberulent proximally, lateral veins moderately prominent, margins glabrous, apices acute; palea keels sparsely to moderately densely scabrous; anthers vestigial (0.1-0.2 mm) or 2.5-3 mm. |
2n | = unknown. |
= unknown. |
Poa paludigena |
Poa porsildii |
|
Distribution |
IA; IL; IN; MI; MN; NC; NJ; NY; OH; PA; VA; WI; WV
|
AK; NT; YT |
Discussion | Poa paludigena is an inconspicuous species restricted to the northeastern United States. It grows in shady bogs and fens, often underneath other plants. Poa trivialis (p. 568) sometimes grows with P. paludigena; the former has distinctly longer ligules and anthers. Plants from the middle Appalachian Mountains are sometimes confused with P. sylvestris (p. 512). Poa paludigena is generally shorter and more slender, has shorter panicles with only 1-2 branches per node, is glabrous between the lemma veins and on the palea keels, has shorter anthers, and grows in colder habitats. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Poa porsildii is an alpine, calciphilic, mesophilic, dioecious species that grows from eastern Alaska to the western Northwest Territories. It differs from P. cusickii subsp. purpurascens (p. 562) in having panicles with laxer, smooth, and more slender branches, lemmas that are usually glabrous, and in having staminate plants. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 24, p. 572. | FNA vol. 24, p. 563. |
Parent taxa | Poaceae > subfam. Pooideae > tribe Poeae > Poa > subg. Poa > sect. Oreinos | Poaceae > subfam. Pooideae > tribe Poeae > Poa > subg. Poa > sect. Madropoa > subsect. Epiles |
Sibling taxa | ||
Name authority | Fernald & Wiegand | Gjaerev. |
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