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

woodland bluegrass

Hartz's bluegrass

Habit Plants perennial; not rhizomatous, not stoloniferous, loosely tufted, sometimes appearing shortly rhizomatous, loosely to densely tufted. Plants perennial; not glaucous; densely to loosely tufted, not rhizomatous,occasionally weakly stoloniferous.
Culms

30-120 cm, bases often decumbent.

10-33(45) cm, usually decumbent, terete;

nodes terete, 0(1) exserted.

Sheaths

closed for (1/20) 1/2-7/8 their length, terete, throats frequently ciliate near the point of fusion;

ligules 0.5-2.7 mm, smooth or sparsely scabrous, truncate to obtuse;

blades 0.7-5 mm wide, flat, thin, lax.

closed for 1/7 – 1/5(1/3) their length, terete, usually lustrous, bases of basal sheaths glabrous;

ligules (1.5)2-7 mm, smooth or sparsely scabrous, margins usually decurrent, apices obtuse to acuminate;

innovation blades similar in texture and shape to those of the culms;

cauline blades 2-9 cm, gradually increasing or decreasing in length upwards, 1.5-3 mm wide, folded to involute, moderately thick, soft, abaxial surfaces smooth, adaxial surfaces smooth or somewhat scabrous, usually glabrous, infrequently sparsely hispidulous, apices narrowly prow-shaped.

Basal branching

mainly pseudointravaginal.

extra- and intravaginal.

Panicles

(6.7)9-20 cm, open, narrowly conical at maturity;

nodes with (2)3-10 branches per node;

branches (2)3-7 cm, spreading to eventually reflexed, straight, angled, angles several, densely scabrous, with 1-11 spikelets.

2.5-6(12) cm, erect, narrowly lanceolate, contracted or narrowly ovate in some bulbiferous plants, moderately congested, with 7-40 spikelets;

nodes with (1)2(4) branches;

branches 1-3 cm, erect to ascending, straight, sulcate, smooth or sparsely to moderately scabrous, with 1-10 spikelets in the distal 1/3 – 2/3.

Spikelets

2.5-4.4 mm, laterally compressed;

florets 2-3(4);

rachilla internodes longer than (1)1.2 mm, smooth, glabrous.

4.8-7.4 mm, lengths 3.5-4 times widths, lanceolate, weakly laterally compressed, sometimes bulbiferous, lustrous;

florets (2)3-5(6), normal or bulb-forming;

rachilla internodes 0.8-2 mm, smooth, sometimes sparsely hispidulous.

Glumes

distinctly keeled, keels scabrous;

lower glumes 1(3)-veined;

upper glumes shorter than or subequal to the lowest lemmas;

calluses webbed;

lemmas 2.1-3.1 mm, broadly lanceolate, distinctly keeled, keels and marginal veins short-villous, extending to near the apices on the keels, lateral veins prominent, softly puberulent to short-villous, intercostal regions usually sparsely softly puberulent, smooth, apices obtuse to acute;

palea keels softly puberulent at midlength, apices finely scabrous;

anthers 1-1.8 mm.

mostly broadly scarious, somewhat lustrous, keels indistinct, smooth or sparsely scabrous distally;

lower glumes 3-veined;

upper glumes frequently exceeding the lowest lemmas;

calluses glabrous or with a crown of hairs, hairs to 2 mm;

lemmas (3.3)3.5-7 mm, lanceolate, usually weakly keeled, more or less evenly and somewhat loosely to densely hairy over the proximal 1/3-1/2, hairs usually longer than 0.5 mm, sparsely scabrous in the middle 1/3, smooth distally, lateral veins obscure, margins weakly inrolled, broadly scarious, glabrous, apices long-scarious, acute to shortly obtuse, often erose, often bronze-colored below the apices;

palea keels sparsely scabrous, softly puberulent at midlength, intercostal regions softly puberulent;

anthers usually all aborted late in development and 0.8-1.8 mm, infrequently well developed and 2-2.8 mm.

2n

= 28.

= 63, 70.

Poa sylvestris

Poa hartzii

Distribution
from FNA
AL; AR; DC; DE; FL; GA; IA; IL; IN; KS; KY; LA; MD; MI; MN; MO; MS; NC; NE; NJ; NY; OH; OK; PA; SC; SD; TN; TX; VA; WI; WV; ON
[WildflowerSearch map]
[BONAP county map]
from FNA
AK; NT; NU; QC; Greenland
[BONAP county map]
Discussion

Poa sylvestris grows in southeastern Canada and throughout much of the eastern United States, mainly at low elevations in woodlands, especially in riparian zones. It is easily distinguished from P. wolfii (p. 514) by its smaller, more numerous spikelets and lemmas that are usually sparsely hairy between the veins. Plants from the middle Appalachian Mountains have been confused with P. paludigena (p. 572); P. sylvestris is usually larger, has more than 2 branches per panicle node, is pubescent between the lemma veins and palea keels, and has larger anthers.

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

Poa hartzii grows only in the high arctic. It generally grows on open ground, on sandy or clayey soils, or on slumping slopes of old marine terraces. It carries two chloroplast genomes within its populations; one of these links it to P. secunda (p. 586) and P. ammophila (see next), the other to P. glauca (p. 576). Morphologically, it is closest to P. secunda and P. ammophila.

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

Key
1. Spikelets bulbiferous
subsp. vrangelica
1. Spikelets not bulbiferous.
→ 2
2. Lemmas 5.5-7 mm long; anthers well developed, 2-2.8 mm long
subsp. alaskana
2. Lemmas 3.3-5.4 mm long; anthers usually aborted and shorter than 1.5 mm
subsp. hartzii
Source FNA vol. 24, p. 512. FNA vol. 24, p. 589.
Parent taxa Poaceae > subfam. Pooideae > tribe Poeae > Poa > subg. Poa > sect. Sylvestres Poaceae > subfam. Pooideae > tribe Poeae > Poa > subg. Poa > sect. Secundae > subsect. Secundae
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. saltuensis, P. secunda, P. sierrae, P. stebbinsii, P. stenantha, P. strictiramea, P. sublanata, P. suksdorfii, P. supina, 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. 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
Subordinate taxa
P. hartzii subsp. alaskana, P. hartzii subsp. hartzii, P. hartzii subsp. vrangelica
Name authority A. Gray Gand.
Web links