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

bulbous blue grass

abbreviated bluegrass, dwarf blue grass, northern blue grass, short bluegrass

Habit Plants perennial; densely tufted, not rhizomatous, not stoloniferous. Plants perennial; not or scarcely glaucous; densely tufted, not stoloniferous, not rhizomatous.
Culms

15-60 cm, erect or spreading, bases bulbous.

5-15(20) cm, slender, leafless above the basal tuft.

Sheaths

closed for about 1/4 their length, terete, lowest sheaths with swollen bases;

ligules 1-3 mm, smooth or scabrous, apices obtuse to acute;

blades 1-2.5 mm wide, flat, thin, lax, soon withering.

closed for 1/10 – 1/4 their length, terete;

ligules 0.4-5.5 mm, milky white to hyaline, smooth or scabrous, apices truncate to acute;

blades 0.8-1.5(2) mm wide, involute, moderately thick, soft, apices narrowly prow-shaped.

Basal branching

intravaginal.

all or mainly intravaginal.

Panicles

3-12 cm, ovoid;

nodes with 2-5 branches;

branches ascending to spreading, terete, usually smooth or sparsely scabrous, infrequently moderately scabrous.

1.5-5 cm, erect, lanceoloid to ovoid, contracted, congested;

nodes with 1-3 branches;

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

pedicels usually shorter than the spikelets.

Spikelets

3-5 mm, laterally compressed, usually bulbiferous;

florets 3-7, the basal floret, and sometimes additional florets, normal;

rachilla internodes smooth, glabrous.

4-6.5 mm, laterally compressed, rarely bulbiferous, frequently strongly anthocyanic;

florets 2-5, rarely bulb-forming;

rachilla internodes usually shorter than 1 mm, smooth or scabrous.

Glumes

keeled, keels scabrous;

lower glumes 3-veined;

upper glumes shorter than or subequal to the lowest lemmas;

calluses webbed or glabrous;

lemmas 3-4 mm, lanceolate, keeled, glabrous or the keels and marginal veins short- to long-villous, intercostal regions glabrous or softly puberulent, apices acute;

paleas scabrous, keels often softly puberulent at midlength;

anthers 1.2-1.5 mm and functional, sometimes aborted late in development, sometimes not developed.

subequal to slightly longer than the adjacent lemmas, lanceolate to broadly lanceolate, distinctly keeled, keels smooth;

lower glumes (1)3-veined, lateral veins often faint and short;

upper glumes exceeding or exceeded by the upper florets;

calluses glabrous or webbed;

lemmas 3-4.6 mm, lanceolate to broadly lanceolate, distinctly keeled, thin, keels and marginal veins usually short- to long-villous, hairs extending along 3/4 - 5/6 of the keel, infrequently glabrous, intercostal regions glabrous or softly puberulent to short-villous, apices acute;

palea keels scabrous, often short-villous to softly puberulent at midlength, sometimes glabrous;

anthers 0.2-1.2(1.8) mm.

2n

= 14, 21, 28, 39, 42, 45.

= 42.

Poa bulbosa

Poa abbreviata

Distribution
from FNA
AR; AZ; CA; CO; CT; DE; GA; IA; ID; IL; IN; KS; KY; LA; MA; MD; MI; MN; MO; MT; NC; ND; NE; NJ; NM; NV; NY; OH; OK; OR; PA; SD; TN; TX; UT; VA; VT; WA; WI; WV; WY
[WildflowerSearch map]
[BONAP county map]
from FNA
AK; CA; CO; ID; MT; NV; OR; UT; WY; AB; BC; NT; NU; YT; Greenland
[BONAP county map]
Discussion

Poa bulbosa is a European species that is now established in the Flora region. In southern Europe and the Middle East, it is considered an important early spring forage.

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

Poa abbreviata is an alpine and circumarctic species which has two subspecies in the western Cordilleras, and one in the high arctic. It grows mainly on frost scars and mesic rocky slopes, usually on open ground. In rare cases where the lemmas and calluses of P. abbreviata ate glabrous, it can be confused with P. lettermanii (p. 580), but that species has shorter spikelets and glumes that are longer than the adjacent florets.

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

Key
1. Spikelets not bulbiferous
subsp. bulbosa
1. All or some spikelets bulbiferous
subsp. vivipara
1. Lemmas glabrous; calluses webbed
subsp. marshii
1. Lemmas usually with hairs over the veins; calluses glabrous or webbed, rarely both the lemmas and calluses glabrous.
→ 2
2. Anthers 0.2-0.8 mm long; lemma intercostal regions hairy
subsp. abbreviata
2. Anthers 0.6-1.2(1.8) mm long; lemma intercostal regions glabrous or hairy
subsp. pattersonii
Source FNA vol. 24, p. 516. FNA vol. 24.
Parent taxa Poaceae > subfam. Pooideae > tribe Poeae > Poa > subg. Poa > sect. Arenariae 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. 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. sylvestris, P. tenerrima, P. tracyi, P. trivialis, P. unilateralis, P. wheeleri, P. wolfii, P. ×gaspensis, P. ×limosa, P. ×nematophylla
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. sylvestris, P. tenerrima, P. tracyi, P. trivialis, P. unilateralis, P. wheeleri, P. wolfii, P. ×gaspensis, P. ×limosa, P. ×nematophylla
Subordinate taxa
P. bulbosa subsp. bulbosa, P. bulbosa subsp. vivipara
P. abbreviata subsp. abbreviata, P. abbreviata subsp. marshii, P. abbreviata subsp. pattersonii
Name authority L. R. Br.
Web links