Poa macrantha
Poa paucispicula
dune bluegrass, large flower sand dune blue grass, sand-dune blue grass, seashore blue grass
Alaska blue grass, few-flower bluegrass
(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.
10-30 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.
closed for 1/4 - 3/5 their length, terete;
ligules 1-2 mm, smooth or sparsely scabrous, truncate to obtuse;
blades 1-3 mm wide, flat, thin, soft, apices broadly prow-shaped.
mostly intravaginal, some extravaginal.
mainly extravaginal.
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.
2.5-10 cm, lax to nearly erect, open, sparse, with 1-2 branches per node;
branches (2)3-6 cm, ascending to spreading, lower branches infrequently reflexed, lax or drooping, capillary, terete to slightly sulcate, usually smooth, rarely some branches within a panicle sparsely scabrous, with 1-3(5) spikelets.
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.
4-6 mm, laterally compressed, broadly lanceolate to ovate, usually dark purple, with 3-5 florets;
rachilla internodes smooth, glabrous.
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.
lanceolate to broadly lanceolate, thin, distinctly keeled, keels smooth or nearly so;
lower glumes 1-veined;
upper glumes shorter than or subequal to the lowest lemmas;
calluses sparsely webbed;
lemmas 3-4 mm, broadly lanceolate, usually strongly purple, distinctly keeled, thin, keels and marginal veins short- to long-villous, keels hairy for 1/2-1/3 their length, lateral veins glabrous, intercostal regions smooth, glabrous, margins glabrous, not infolded, apices acute, sometimes slightly bronze-colored;
palea keels sparsely scabrous at midlength;
anthers 0.4-1 mm.
= 28.
= 28, 42.
Poa macrantha
Poa paucispicula
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.)
Poa paucispicula grows in arctic and alpine regions, from the north coast of Alaska and the western Northwest Territories south to Washington, Idaho, and Wyoming; it also grows in arctic far east Russia. It is a delicate species that prefers open, mesic, rocky slopes. It has sometimes been included in P. leptocoma (p. 573), a member of Poa sect. Oreinos. It differs from P. leptocoma in having smoother branches, fewer spikelets, and broader glumes. Chloroplast DNA studies confirm that it is not closely related to species of sect. Oreinos; ITS data support its relationship to P. leptocoma.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
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