Poa subsect. Aphanelytrum (Hack.) Soreng & P.M. Peterson, 2016

Peterson, Paul M. & Soreng, Robert J., 2016, A revision of Poa subsection Aphanelytrum (Poaceae, Pooideae, Poaeae, Poinae); and a new species, Poa auriculata, PhytoKeys 63, pp. 107-125 : 109-110

Poa subsect. Aphanelytrum (Hack.) Soreng & P.M. Peterson comb. & stat. nov.

Poa subsect. Aphanelytrum within Poa subg. Poa supersect. Homalopoa (Dumort.) Soreng & L.J. Gillespie sect. Dioicopoa E. Desv., see Gillespie et al. 2007

Basionym.

Brachyelytrum subg. Aphanelytrum Hack., Die Nat. Pflanzenfam., Nachträge zu Teil II, Abteilung 2. 42. 1897.

Aphanelytrum (Hack.) Hack., Oesterr. Bot. Z. 52: 12. 1902. Aphanelytrum procumbens (Hack.) Hack., Oesterr. Bot. Z. 52: 13, text f. 1902.

Aphanelytrum Hack. ex Sodiro, Anales Univ. Centr. Ecuador 3(25): 480. 1889, nom. nud.

Type species.

Based on Brachyelytrum procumbens Hack. ≡ Aphanelytrum procumbens (Hack.) Hack. ≡ Poa hitchcockiana .

Diagnosis.

Poa subsect. Aphanelytrum differs from most species of Poa in having stooling perennials with decumbent to spreading culm bases that continuously branch and often root at low to mid-culm nodes, glabrous spikelets with long rachillas 1.2 -4.2 mm long, short glumes less than ½ the length of the florets, and lemmas with bifid apices that are mucronate to short-awned.

Description.

Stooling perennials with intravaginal innovations. Culms 14-80 (-100) cm tall, decumbent to spreading near base, culm bases that continuously branch and often root at low to mid-culm nodes. Leaf blades 3-14 cm long, 0.2-5 (-5.5) mm wide, flat to loosely involute; ligules 1-3 mm long, membranous. Panicles few-flowered with 5-22 spikelets. Spikelets 5-18 mm long, 2-4-flowered, membranous, glabrous, disarticulating above the glumes and between the florets; rachilla 1.2-4.2 mm long, terete in cross section, often prolonged above upper floret; callus glabrous; glumes 0.1-3.5 mm long, less than ½ the length of the florets, 0-3 (-4)-veined; lemmas 2.2-9.6 mm long, 3- or 5-veined, lanceolate or ovate, apex bifid, mucronate to short-awned, if awned up to 2 mm long; paleas 2-7 mm long, apex bifid; lodicules 2, glabrous; stamens 3, anthers 2-4.7 mm long; ovaries glabrous. Caryopses compressed laterally or unknown.

Three species of northern to central Andes of South America.

Key to the species of Poa subsection Aphanelytrum