ROSE—MEXICAN AND CENTRAL AMERICAN PLANTS. 289 
Poa subunifiora Kanth, Rey. Gram. 1: 115, 339. pl. 83. 1830, 
Cinnastrum poacforime Fourn, Mex. Pl. 2: 91. 1881. 
Collected at an altitude of 3,240 meters, August 7 and 8, 1901 (no. 6025). 
Agrostis tolucensis II. B. K. Noy. Gen. & Sp. 1: 135. 1819. 
dgraulus mevicanus Presl, Rel. Haenk. 1: 286. 1830. 
Collected at an altitude of 3,240 meters, August 22, 1901 (no. 6296a). 
Calamagrostis tolucensis (H. B. K.) Trin. in Steud. Nom. IT, 1: 250. 1840. 
Deyeuvia tolucensis WH. B. K. Nov. Gen. & Sp. Pl. 1: 148. 1815. 
Calamagrostis sesquitriflora Steud. 1. ¢. 
Collected at an altitude of 3,940 and 8,580 meters, August 22, 1901 (nos. 6298 and 
6298a). 
Trisetum tolucense (II. B. K.) Kunth, Rey. Gram. 1: 101. 297. pl. 60. 1830. 
Avena tolucensis 1. BL IK. Nov. Gen. & Sp. Pl 1: 148. 1815, 
Collected at an altitude of 3,550 meters, August 22, 1901 (no. 6299). 
Trisetum rosei Scribn. & Merrill sp. nov. 
A densely tufted, nearly glabrous, green or purplish perennial, 20 to 45 em. high, 
with numerous firm leaves, dense spike-like panicles, and very strongly pilose 
flowering glumes; culms rather stout, densely puberulent above; sheaths exceeding 
the internodes, overlapping, minutely puberulent; ligule about 2 mm. long, truncate; 
leaf-blades plane or becoming involute in drying, glabrous beneath, prominently 
striate and minutely pubescent above, those of the culm one or two, 3 to 5 mm. 
wide, 5 to 7 em. long, erect, the basal ones numerous, 5 to 12 em. long; panicle 
purplish, 6 to 10¢m. long, 10 to 15 mm. in diameter, rather densely flowered, the 
branches | to 3 cm. long, appressed, flower-bearing throughout, the axils and branches 
densely and softly pubescent, spikelets about 6 mum. long, 2-flowered; empty glumes 
ovyate-lanceolate, the first 4 min., the second 5 mm. in length, glabrous, except on 
the ciliate margins above, with appressed or spreading white hairs, the first 5 num., 
the second 4.5 mm. in length, ovate-lanceolate, acute and slightly cleft at the apex, 
bearing a slender, somewhat reflexed ciliate awn just above the middle, about 4 mm. 
in length; palea equaling the glume, hyaline, ovate-lanceolate, sparingly ciliate on 
the margins. 
Collected by J. N. Rose on Mount Popocatepetl, at an altitude of 3,600 meters, 
August 7 and 8, 1901 (no. 6016, type); also Rose no. 5979, from the same locality but 
higher altitude (alt. 4,115 meters), is referred here, it being a lower, more cespitose 
form. This species is very similar in aspect to Trisetiin tolucense (H. B. kK.) Benth., 
but is at once distinguished from that species by its very strongly pilose flowering 
glume, ciliate awns, and puberulent sheaths and leaves. 
Trisetum rosei tenerum Scribn. & Merrill, var. nov. 
Aslenderer form 20 to 40 em. high, with long-exserted panicle, much shorter 
leaves, and smaller spikelets than in the species; culms very slender; culm leaves 
one or two, 2 to 3 em. long, the basal ones very narrow, 5 to 7 cm. long; panicles 
densely flowered, 4 to 7 em. long; spikes 4.5 to 5 mm. long, otherwise as in the 
species. 
Collected by J. N. Rose on Mount Popocatepetl at an altitude of 3,160 meters, 
August 7 and 8, 1901 (no, 6016, type); also another specimen from the same locality 
without number, collected August 22, 1901, is referred here; also collected on Mount 
Orizaba, by J. N. Rose and Robert Hay, July 25, 26, 1901 (no. 6348). 
Poa conglomerata Rupr. Bul. Acad, Brux. 9%: 235. 1842. nom. nud. ex Peyr. in 
Linnea 30: 8. 1859. 
Collected at an altitude of 3,390 meters, August 7 and 8, 1901, by J. N. Rose 
(no. 6026a); also at the same station and date, altitude 3,540 meters (no. 6026). 
17667—voL vil, pT 4—05 2 
