Thesis), narrowly lanceoloid to ovoid, congested (except in flowering), with (15?25?0 (more than 100) spikelets; rachis with 1? branches per node; primary branches erect, fairly stout, terete to weakly angled, smooth or scabrous, prickles not confined to angles; BMS-986020 site lateral pedicels 1/5?/4 the spikelet in length, sparsely to fairly densely scabrous, prickles fine to fairly coarse; longest branches 1? cm, with 3?5(?5) spikelets. Spikelets (3?4?(?2) mm long, to 3 ?long as wide, sub-lustrous, broadly lanceolate to ovate, laterally compressed, not sexually dimorphic; not bulbiferous; florets 2?(?3), pistillate or staminate; rachilla internodes terete, usually 0.8?.3 mm long, smooth, glabrous, sparsely hispidulous, or sparsely softly puberulent to short villous; glumes lanceolate, distinctly keeled, keel smooth or sparingly scabrous, margins fairly broadly scarious, edges smooth or lightly scabrous; apices obtuse to acute; lower glumes distinctly shorter than the lowest lemma, 1?-veined; upper glumes lanceolate, slightly shorter than lowest lemma, 3-veined; calluses glabrous; lemmas (3?4.5? mm long, lanceolate, pallid green, commonly anthocyanic distinctly keeled, keels and marginal veins short to long villous or softly puberulent, or glabrous, intermediate veins short villous to softly puberulent or glabrous, between veins softly puberulent or glabrous, smooth or sparsely finely scabrous, intermediate veins obscure to moderately prominent, margins narrowly scarious to hyaline, edges smooth or lightly scabrous, apices acute to obtuse, sometimes retusely notched (to 0.25 mm deep); palea keels coarsely scabrous, medially sometimes softly puberulent or long villous, between keels glabrous or infrequently puberulent. Flowers chasmogamous; lodicules of pistillate plants 0.6?.85 mm long, broadly lanceolate to ovate, with or without a brief lateral lobe from below the middle (lodicules rudimentary in staminate plants); anthers 2?.2 mm long, or all vestigial and 0.1?.2 mm long. Caryopses 2?.5 mm long, elliptical in side-view, subtrigonous in cross-section, honey-brown, sulcus broad and shallow, hilum 0.25 mm long, round, grain adherent to the palea. Distribution. The species is widespread in North America and occurs in Roc-A biological activity southwestern and south central Canada, western USA, and northern Mexico in Baja California, Chihuahua, Coahuila, and Sonora.Revision of Poa L. (Poaceae, Pooideae, Poeae, Poinae) in Mexico: …Ecology. This dioecious, weakly rhizomatous species occurs in the mountains on open forested slopes derived from calcareous and igneous substrates. It is sometimes strictly pistillate and apomictic. Flowering principally in the spring. Discussion. This species provides good springtime forage where it is abundant and all three subspecies occur in Northern Mexico (Soreng and Van Devender 1989; Soreng et al. 2003a). The sex of specimens is indicated here for purposes of estimating the breeding system (geographical and ecological extent of sexual versus asexual reproduction), along with numbers of individuals of each sex where populations were evaluated. Where only or predominately pistillate plants are found, the species usually reproduces apomicticly by seed. No pollen is required to stimulate seed development in apomictic plants of this species (i.e., they are not pseudogamous). Sexual reproduction predominates where staminate plants are found and relatively numerous. Seed is commonly set in 20 or more of flowers in the apomictic populations and usua.Thesis), narrowly lanceoloid to ovoid, congested (except in flowering), with (15?25?0 (more than 100) spikelets; rachis with 1? branches per node; primary branches erect, fairly stout, terete to weakly angled, smooth or scabrous, prickles not confined to angles; lateral pedicels 1/5?/4 the spikelet in length, sparsely to fairly densely scabrous, prickles fine to fairly coarse; longest branches 1? cm, with 3?5(?5) spikelets. Spikelets (3?4?(?2) mm long, to 3 ?long as wide, sub-lustrous, broadly lanceolate to ovate, laterally compressed, not sexually dimorphic; not bulbiferous; florets 2?(?3), pistillate or staminate; rachilla internodes terete, usually 0.8?.3 mm long, smooth, glabrous, sparsely hispidulous, or sparsely softly puberulent to short villous; glumes lanceolate, distinctly keeled, keel smooth or sparingly scabrous, margins fairly broadly scarious, edges smooth or lightly scabrous; apices obtuse to acute; lower glumes distinctly shorter than the lowest lemma, 1?-veined; upper glumes lanceolate, slightly shorter than lowest lemma, 3-veined; calluses glabrous; lemmas (3?4.5? mm long, lanceolate, pallid green, commonly anthocyanic distinctly keeled, keels and marginal veins short to long villous or softly puberulent, or glabrous, intermediate veins short villous to softly puberulent or glabrous, between veins softly puberulent or glabrous, smooth or sparsely finely scabrous, intermediate veins obscure to moderately prominent, margins narrowly scarious to hyaline, edges smooth or lightly scabrous, apices acute to obtuse, sometimes retusely notched (to 0.25 mm deep); palea keels coarsely scabrous, medially sometimes softly puberulent or long villous, between keels glabrous or infrequently puberulent. Flowers chasmogamous; lodicules of pistillate plants 0.6?.85 mm long, broadly lanceolate to ovate, with or without a brief lateral lobe from below the middle (lodicules rudimentary in staminate plants); anthers 2?.2 mm long, or all vestigial and 0.1?.2 mm long. Caryopses 2?.5 mm long, elliptical in side-view, subtrigonous in cross-section, honey-brown, sulcus broad and shallow, hilum 0.25 mm long, round, grain adherent to the palea. Distribution. The species is widespread in North America and occurs in southwestern and south central Canada, western USA, and northern Mexico in Baja California, Chihuahua, Coahuila, and Sonora.Revision of Poa L. (Poaceae, Pooideae, Poeae, Poinae) in Mexico: …Ecology. This dioecious, weakly rhizomatous species occurs in the mountains on open forested slopes derived from calcareous and igneous substrates. It is sometimes strictly pistillate and apomictic. Flowering principally in the spring. Discussion. This species provides good springtime forage where it is abundant and all three subspecies occur in Northern Mexico (Soreng and Van Devender 1989; Soreng et al. 2003a). The sex of specimens is indicated here for purposes of estimating the breeding system (geographical and ecological extent of sexual versus asexual reproduction), along with numbers of individuals of each sex where populations were evaluated. Where only or predominately pistillate plants are found, the species usually reproduces apomicticly by seed. No pollen is required to stimulate seed development in apomictic plants of this species (i.e., they are not pseudogamous). Sexual reproduction predominates where staminate plants are found and relatively numerous. Seed is commonly set in 20 or more of flowers in the apomictic populations and usua.
