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Howell's blue grass

Suksdorf's bluegrass, western blue grass

Habit Plants usually annual, rarely longer-lived; densely tufted, tuft bases narrow; not stoloniferous, not rhizomatous. Plants perennial; not glaucous; densely tufted, not stoloniferous, not rhizomatous.
Culms

(10) 25-80(120) cm tall, 0.4-1.75 mm thick, usually erect;

nodes terete, usually 1-2 exserted.

7-25 cm.

Sheaths

closed for 1/2 - 7/8 their length, usually weakly compressed and keeled, usually scabrous, rarely smooth;

ligules 1.5-5(10) mm, smooth or scabrous, acute;

blades 1-7(10) mm wide, flat, lax, soft, finely scabrous, apices narrowly prow-shaped, cauline blades 2-10 cm.

closed for 1/7-1/4(1/3) their length, terete;

ligules of cauline leaves 1-3 mm, milky white, usually densely scabrous, sometimes smooth, ligules of the upper innovation leaves 0.5-2.5 mm;

innovation blades adaxially scabrous, hispidulous, or puberulent on and between the veins, lacking papillae on the long cells (at 100x);

cauline blades folded to involute, moderately thick, soft or moderately firm, apices narrowly prow-shaped, flag leaf blades 1-2 mm wide, adaxial surfaces with 5-9 well-spaced ribs.

Basal branching

intravaginal.

all or mainly intravaginal.

Panicles

10-25(30) cm, erect, eventually open, with (1)3-5(7) branches per node;

branches eventually spreading or reflexed, fairly straight, angled, angles usually moderately to densely scabrous, rarely sparsely scabrous.

3-6 cm, erect, narrowly lanceoloid, contracted, moderately congested;

nodes with 1-2 branches;

branches to 1.5 cm, erect, slender, terete, sulcate or angled, smooth or the angles moderately scabrous;

pedicels shorter than the spikelets.

Spikelets

(2)4-6 mm, laterally compressed, with 2-5 florets;

rachilla internodes about 1 mm, smooth, usually softly puberulent, infrequently glabrous.

4.2-7 mm, laterally compressed, often strongly anthocyanic;

florets 2-4;

rachilla internodes 1-1.5 mm, smooth, sometimes sparsely hispidulous.

Glumes

slightly unequal, lanceolate, distinctly keeled, keels and sometimes the lateral veins sparsely to moderately scabrous;

lower glumes 1-3-veined;

upper glumes shorter than or subequal to the lowest lemmas;

calluses of some or all florets sparsely webbed;

lemmas 2.5-3.5 mm, lanceolate to narrowly lanceolate, distinctly keeled, crisply puberulent proximally, hairs evenly distributed, finely scabrous distally, lateral veins obscure to prominent, margins narrowly hyaline, glabrous, apices narrowly acute, infrequently anthocyanic;

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

anthers 3, 0.2-1 mm.

lanceolate, distinctly keeled, keels smooth;

lower glumes shorter than to equaling the lowest lemmas, 3-veined;

upper glumes frequently exceeding the lowest lemmas, 3-5-veined, exceeded by the upper lemmas;

calluses glabrous;

lemmas 4.1-5.8 mm, narrowly lanceolate, distinctly keeled, thin, glabrous, apices acute;

palea keels scabrous;

anthers 0.8-1.2(1.7) mm, infrequently aborted late in development.

2n

= unknown.

= unknown.

Poa howellii

Poa suksdorfii

Distribution
from FNA
CA; OR; WA; BC
[WildflowerSearch map]
[BONAP county map]
from FNA
OR; WA; BC
[WildflowerSearch map]
[BONAP county map]
Discussion

Poa howellii grows primarily on rocky banks and wooded slopes, from the coastal ranges of southern British Columbia to southern California. It differs from P. bolanderi (see above) in having puberulent, rather than smooth or scabrous, lemmas, and in growing at lower elevations, mostly from near sea level to 1000 m.

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

Poa suksdorfii is a high alpine species of open rocky ground in the Pacific Northwest. It used to be interpreted (Hitchcock 1951) as including California populations that are now placed in Poa pringlei (p. 564) or P. keckii (see previous). Poa suksdorfii has narrow panicles like P. pringlei and P. curtifolia (p. 589).

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

Source FNA vol. 24, p. 534. FNA vol. 24, p. 584.
Parent taxa Poaceae > subfam. Pooideae > tribe Poeae > Poa > subg. Poa > sect. Homalopoa Poaceae > subfam. Pooideae > tribe Poeae > Poa > subg. Poa > sect. Abbreviatae
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. 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. 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. supina, P. sylvestris, P. tenerrima, P. tracyi, P. trivialis, P. unilateralis, P. wheeleri, P. wolfii, P. ×gaspensis, P. ×limosa, P. ×nematophylla
Synonyms P. bolanderi var. howellii
Name authority Vasey & Scribn. (Beal) Vasey ex Piper
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