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early bluegrass

dune bluegrass, large flower sand dune blue grass, sand-dune blue grass, seashore blue grass

Habit Plants perennial; loosely tufted or with solitary shoots, shortly rhizomatous. Plants perennial; loosely tufted, rhizomatous and stoloniferous, rhizomes and stolons to 4 m, stout, robust.
Culms

15-60 cm, erect or the bases decumbent, not branching above the base, terete or weakly compressed;

nodes terete, 0-1 exserted.

(7)15-60 cm tall, 1.5-2 mm thick, bases decumbent, terete or weakly compressed, smooth or moderately scabrous below the panicles;

nodes terete, 0(1) exserted.

Sheaths

closed for about 1/2 their length, slightly compressed, distinctly keeled, glabrous, bases of basal sheaths glabrous, distal sheath lengths 4-60 times blade lengths;

collars of proximal leaves usually retrorsely scabrous or pubescent distally and about the throat;

ligules 0.5-4 mm, smooth or scabrous, apices truncate to acute;

innovation blades similar to the cauline blades;

cauline blades 1-4 mm wide, usually flat, sometimes slightly folded, smooth or sparsely scabrous, primarily over the veins, apices broadly prow-shaped, blades steeply reduced in length distally, flag leaf blades 0.2-3(6) cm.

closed for about 1/2 their length, terete, glabrous or sparsely retrorsely scabrous, bases of basal sheaths glabrous, distal sheath lengths 1.7-4(6) times blade lengths;

collars smooth, glabrous;

ligules 1-5 mm, scabrous, truncate to acute, ciliolate;

innovation blades to 30 cm, moderately to densely scabrous or hispidulous on and between the veins;

cauline blades subequal in length, 2-4 mm wide, involute, thick, somewhat arcuate, firm, abaxial surfaces smooth or moderately to densely scabrous or hispidulous on and between the veins, apices narrowly prow-shaped, flag leaf blades 1-10 cm.

Basal branching

mainly extravaginal.

mostly intravaginal, some extravaginal.

Panicles

5-15 cm, erect or lax, pyramidal, open, sparse, with 20-80 spikelets, proximal internodes usually 3+ cm;

nodes usually with 2 branches;

branches (2)3-7(10) cm, spreading to reflexed, straight, angled, angles scabrous, with 2-8(10) spikelets.

3-15 cm, erect, ovoid to lanceolate, contracted, often interrupted, congested, with 15-80 spikelets, rachises glabrous, smooth to moderately scabrous;

nodes with 1-2 branches;

branches 1-6 cm, erect, stiff, terete to weakly angled, smooth or sparsely to moderately scabrous, with 3-17 spikelets.

Spikelets

5-8 mm, lengths to 3.5 times widths, laterally compressed, not sexually dimorphic;

florets 2-5;

rachilla internodes smooth.

9-17 mm, lengths to 3 times widths, laterally compressed, not sexually dimorphic;

florets 3-6(10);

rachilla internodes smooth, usually hairy, hairs 0.3-0.4+ mm, rarely glabrous.

Glumes

narrowly lanceolate to lanceolate, distinctly keeled;

lower glumes 1-3-veined;

calluses webbed, hairs over 1/3 the lemma length;

lemmas 3-6 mm, lanceolate, distinctly keeled, keels and marginal veins sparsely short- to long-villous, lateral veins moderately prominent, intercostal regions glabrous or the upper florets in the spikelets softly puberulent, margins glabrous, apices acute;

palea keels scabrous, softly puberulent at midlength;

anthers vestigial (0.1-0.2 mm) or 2-3.5 mm.

broadly lanceolate, subequal to the adjacent lemmas, distinctly keeled, keels sparsely scabrous near the apices;

lower glumes 3-veined;

upper glumes usually 7+ mm, 3-5-veined;

calluses usually with a crown of hairs, sometimes glabrous or diffusely webbed;

lemmas (6)7.5-11 mm, lanceolate, 5-7(11)-veined, distinctly keeled, keels and marginal veins, and sometimes the lateral veins, short-villous to softly puberulent, intercostal regions smooth or scabrous, glabrous or softly puberulent, margins glabrous, apices acute;

palea keels scabrous, intercostal regions glabrous;

anthers vestigial (0.1-0.2 mm) or (2)3-4(5) mm.

2n

= 28.

= 28.

Poa cuspidata

Poa macrantha

Distribution
from FNA
AL; DC; DE; GA; IN; KY; LA; MD; NC; NJ; NY; OH; PA; SC; TN; VA; WV
[WildflowerSearch map]
[BONAP county map]
from FNA
AK; CA; OR; WA; BC
[WildflowerSearch map]
[BONAP county map]
Discussion

Poa cuspidata is a common species of forest openings in the Appalachian Mountains. It is an eastern counterpart of P. arnowiae (see previous), P. tracyi (p. 543), and P. nervosa (see next). Like those species, it is sequentially gynomonoecious.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Poa macrantha is a dioecious coastal sand dune species that grows from southern Alaska to northern California. It competes better than P. douglasii (see previous) with the invasion of its habitat by Ammophila and other exotic species. It used to be treated as a subspecies of P. douglasii; a few intermediates with that species have been found around the mouth of Little River, California. Although clearly related, the two species are reasonably divergent in a number of characters. Poa macrantha is readily distinguished from P. douglasii by its glabrous rachises and usually longer glumes and lemmas.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Source FNA vol. 24, p. 545. FNA vol. 24, p. 551.
Parent taxa Poaceae > subfam. Pooideae > tribe Poeae > Poa > subg. Poa > sect. Madropoa > subsect. Poa Poaceae > subfam. Pooideae > tribe Poeae > Poa > subg. Poa > sect. Madropoa > subsect. Madropoa
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. 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. 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
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. 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. 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
Synonyms P. douglasii subsp. macrantha
Name authority Nutt. Vasey
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