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bulbous blue grass

ocean bluff blue grass, San Francisco bluegrass, sea-bluff bluegrass

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

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

5-40 cm, erect or ascending, frequently decumbent, terete, with 0-2 exserted nodes.

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(1/5) their length, terete, smooth, glabrous, bases of basal sheaths glabrous, distal sheath lengths 1-4 times widths;

ligules 2-6 mm, smooth or sparsely scabrous, obtuse to acute;

innovation blades usually 1-1.5 mm wide, thin, soon withering, and distinctly narrower than the cauline blades, infrequently wider, flat, and a bit fleshy as in the cauline blades, or involute;

cauline blades gradually reduced in length distally, 2-5 mm wide, flat or folded, soft, thin and soon withering or moderately thick and somewhat fleshy and retaining their form, smooth, apices narrowly to broadly 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.

3-7 cm, erect, nearly cylindrical, contracted, congested, with (20)30-80(120) spikelets;

nodes with 3-7 branches;

branches 0.5-1.5(4.5) cm, erect, usually angled, infrequently terete or sulcate, angles usually moderately to densely scabrous, infrequently smooth with dense papillae and weak-angled, with 2-10 spikelets in the proximal 2/3;

pedicels 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.

4.5-7 mm, lengths to 3.5 times widths, lanceolate to narrowly ovate, drab;

florets 3-5;

rachilla internodes usually shorter than 1 mm, smooth.

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.

lanceolate, slightly unequal, distinctly keeled, keels papillate or scabrous;

lower glumes 3-veined;

calluses glabrous or with a crown of hairs, hairs 0.1-0.2 mm;

lemmas 3-4.5 mm, lanceolate, distinctly keeled, glabrous or the keels and marginal veins short-villous to midlength, intercostal regions sparsely puberulent near the base, margins glabrous, apices acute;

palea keels scabrous, sometimes softly puberulent at midlength;

anthers 1.5-3 mm.

2n

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

= 42, 84.

Poa bulbosa

Poa unilateralis

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
CA; OR; WA
[WildflowerSearch map]
[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 unilateralis grows on grassy bluffs and cliffs near the Pacific coast of North America, from Washington to California.

(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 villous on the keels and marginal veins for more than 1/3 the length of the lemmas; blades usually involute, the cauline and innovation blades similar
subsp. pachypholis
1. Lemmas glabrous or the keels and marginal veins villous or puberulent for less than 1/5 the length of the lemmas; blades flat or folded, the cauline blades sometimes wider and thicker than the innovation blades
subsp. unilateralis
Source FNA vol. 24, p. 516. FNA vol. 24, p. 594.
Parent taxa Poaceae > subfam. Pooideae > tribe Poeae > Poa > subg. Poa > sect. Arenariae Poaceae > subfam. Pooideae > tribe Poeae > Poa > subg. Poa > sect. Secundae > subsect. Halophytae
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. 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. sylvestris, P. tenerrima, P. tracyi, P. trivialis, P. wheeleri, P. wolfii, P. ×gaspensis, P. ×limosa, P. ×nematophylla
Subordinate taxa
P. bulbosa subsp. bulbosa, P. bulbosa subsp. vivipara
P. unilateralis subsp. pachypholis, P. unilateralis subsp. unilateralis
Name authority L. Scribn.
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