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old-pasture blue grass

Porsild's bluegrass

Habit Plants perennial; not rhizomatous, not stoloniferous, loosely tufted. Plants perennial; densely tufted, not stoloniferous, not rhizomatous.
Culms

20-95 cm tall, 0.8-1.5 mm thick.

(12)17-30(40) cm, erect or the bases decumbent, with (0)1(2) exserted nodes.

Sheaths

closed for 1/3-2/3 their length;

ligules 0.2-3(4) mm, smooth or sparsely scabrous, truncate to obtuse;

blades 1-3.6 (6) mm wide, flat, thin, lax, veins prominent.

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

mainly pseudointravaginal.

intra-vaginal.

Panicles

4-20(24) cm long, less than 1/4 the plant height, lax;

nodes with 1-3 branches;

branches ascending to spreading, lax, angled, angles prominent, 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

3-5.6 mm, laterally compressed;

florets 2-5;

rachilla internodes glabrous, usually shorter than 1 mm.

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

2/3 – 3/4 as long as the adjacent lemmas, distinctly keeled;

lower glumes 1(3)-veined;

upper glumes shorter than or subequal to the lowest lemmas;

calluses webbed;

lemmas 2.4-4 mm, lanceolate to broadly lanceolate, distinctly keeled, usually glabrous, bases of marginal veins rarely sparsely softly puberulent, lateral veins prominent, intercostal regions smooth, minutely bumpy, apices obtuse to sharply acute or acuminate;

palea keels scabrous;

anthers 0.4-1.5 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.

Poa saltuensis

Poa porsildii

Distribution
from FNA
CT; IA; IL; IN; KY; MA; MD; ME; MI; MN; NC; NH; NJ; NY; OH; PA; RI; TN; VA; VT; WI; WV; LB; NB; NS; ON; PE; QC
[WildflowerSearch map]
[BONAP county map]
from FNA
AK; NT; YT
[BONAP county map]
Discussion

Poa saltuensis grows in woodlands of the north-central and northeastern United States and adjacent Canada, extending south to Tennessee. The two subspecies are sometimes treated as species. The variation between the two overlaps and is correlated to some extent with ecology and geography. Poa marcida (p. 512), a western species once included in P. saltuensis, differs in having closed sheaths and attenuate lemmas.

(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.)

Key
1. Anthers 0.4-1 mm long; lemma apices obtuse to acute, firm or scarious for up to 0.25 mm
subsp. languida
1. Anthers 0.9-1.5 mm long; lemma apices acute to acuminate, scarious for 0.25-0.5 mm
subsp. saltuensis
Source FNA vol. 24, p. 510. FNA vol. 24, p. 563.
Parent taxa Poaceae > subfam. Pooideae > tribe Poeae > Poa > subg. Poa > sect. Sylvestres Poaceae > subfam. Pooideae > tribe Poeae > Poa > subg. Poa > sect. Madropoa > subsect. Epiles
Sibling taxa
P. abbreviata, P. alpina, P. alsodes, P. ammophila, P. annua, P. arachnifera, P. arctica, P. arida, P. arnowiae, P. atropurpurea, P. autumnalis, P. bigelovii, P. bolanderi, P. bulbosa, P. chaixii, P. chambersii, P. chapmaniana, P. compressa, P. confinis, P. curtifolia, P. cusickii, P. cuspidata, P. diaboli, P. douglasii, P. eminens, P. fendleriana, P. glauca, P. hartzii, P. howellii, P. infirma, P. interior, P. keckii, P. kelloggii, P. laxa, P. laxa × glauca, P. laxiflora, P. leibergii, P. leptocoma, P. lettermanii, P. macrantha, P. macrocalyx, P. marcida, P. napensis, P. nemoralis, P. nervosa, P. occidentalis, P. paludigena, P. palustris, P. paucispicula, P. piperi, P. porsildii, P. pratensis, P. pringlei, P. pseudoabbreviata, P. reflexa, P. rhizomata, P. secunda, P. sierrae, P. stebbinsii, P. stenantha, P. strictiramea, P. sublanata, P. suksdorfii, P. supina, P. sylvestris, P. tenerrima, P. tracyi, P. trivialis, P. unilateralis, P. wheeleri, P. wolfii, P. ×gaspensis, P. ×limosa, P. ×nematophylla
P. abbreviata, P. alpina, P. alsodes, P. ammophila, P. annua, P. arachnifera, P. arctica, P. arida, P. arnowiae, P. atropurpurea, P. autumnalis, P. bigelovii, P. bolanderi, P. bulbosa, P. chaixii, P. chambersii, P. chapmaniana, P. compressa, P. confinis, P. curtifolia, P. cusickii, P. cuspidata, P. diaboli, P. douglasii, P. eminens, P. fendleriana, P. glauca, P. hartzii, P. howellii, P. infirma, P. interior, P. keckii, P. kelloggii, P. laxa, P. laxa × glauca, P. laxiflora, P. leibergii, P. leptocoma, P. lettermanii, P. macrantha, P. macrocalyx, P. marcida, P. napensis, P. nemoralis, P. nervosa, P. occidentalis, P. paludigena, P. palustris, P. paucispicula, P. piperi, P. pratensis, P. pringlei, P. pseudoabbreviata, P. reflexa, P. rhizomata, P. saltuensis, P. secunda, P. sierrae, P. stebbinsii, P. stenantha, P. strictiramea, P. sublanata, P. suksdorfii, P. supina, P. sylvestris, P. tenerrima, P. tracyi, P. trivialis, P. unilateralis, P. wheeleri, P. wolfii, P. ×gaspensis, P. ×limosa, P. ×nematophylla
Subordinate taxa
P. saltuensis subsp. languida, P. saltuensis subsp. saltuensis
Synonyms P. saltuensis var. microlepis, P. languida
Name authority Fernald & Wiegand Gjaerev.
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