388 Bulletin No. 205 [March, 



Dactylis glomerata L. 



Orchard Grass. Coek's-foot (Figs. 228 and 229) 



Lapham '57, 546, 575 (Plate 2, Fig. 9); Babcock '73, 97; Patterson '76, 50; 

 Flagg '78, 281; Higley and Eaddiu '91, 144; Huett '97, 130. 



Culms rough, 2 to 4 feet tall, in large tufts ; sheaths rough, some- 

 what flattened and keeled ; blades flat, usually rough on both surfaces, 

 3 to 9 inches long, 1 to 6 mm. wide ; panicles 3 to 6 inches long, 

 l)ranches stiff, the spikelets clustered at the ends ; spikelets 3- to 4-flow- 

 ered ; lemmas 4 to 6 mm. long, rough, ciliate on the keel. 



This grass is cultivated extensively as a forage grass. It grows 

 well in shady places. It is a perennial grass which soon becomes per- 

 manently established, being found in waste places thruout the state. 



CHAMPAIGN CO. Urbana, Burrill, June, 1878 ; Urbana, Clinton, June, 1897. 

 CHRISTIAN CO. Tajlorville, Andrews, cook co. iEvanston, Shipman; Winnetka, 

 Sherff 1924. du page CO. Naperville, Umbacli, May, 1896. fulton co. Can- 

 ton, Wolf. JO DAVIESS CO. Without locality, Pepoon. kankakee co. Kanka- 

 kee, Eeecher, July, 1908; Kankakee, Be Selm, June, 1913. lake CO. Eavinia, 

 Gates 1698.1. macon co. Decatur, CloJcey, May, 1899. macoupin co. Carlin- 

 ville, Robertson, May, 1883. peoria co. Peoria, McDonald, June, 1896; Peoria, 

 Brendel. ST. clair co. Without locality, Brendel; Mascoutah, Welsch. stark 

 CO. Wady Petra, F. B. Chase 57. wabash co. Mt. Carmel, Schneck, July, 1888, 

 will CO. Joliet, STceels, June, 1904. 



54. POA L. 



This genus includes a large number of species in the cooler parts of 

 the country. The plants are mostly perennials, but two of our common 

 species are annuals. The spikelets are 2- to 6-flowered, usually in open 

 panicles like those of the well-known Kentucky blue grass. Nearly all 

 our species have a tuft of cobwebby hairs at the base of the lemma. 

 The leaves are narrow, and have a boat-shaped tip ; the ligules are 

 membranous, sometimes 4 or 5 mm. long. 



a. Culms less than a foot tall, low, tufted, winter annuals. 



b. Lemmas webbed at the base, apparently 3-nerved, the intermediate nerves 

 obscure. P. chapmaniana 



bb. Lemmas not webbed at the base, distinctly 5-nerved, the nerves all prom- 

 inent. P. annua 

 na. Culms normally much over a foot tall; perennial grasses. 



b. Lenmias with all the nerves smooth. P. dehilis 



l)b. Lemmas with some of the nerves pubescent. 



c. Intermediate nerves of the lemma prominent. 



d. Midnerve pubescent for its whole length or nearly so ; the second 



glume two-thirds the length of the spikelet. P. sylvestris 



dd. Midnerve never pubescent for its whole length; second glume 



never two-thirds the length of the spikelet. 



e. Plants with long, creeping rootstocks; spikelets usually less 



than 5 mm. long; panicle branches spikelet -l)car]ng below 



the middle. P. pratensis 



ee. Plants without rootstocks; spikelets 5 or 6 mm. long; panicle 



branches spikelet-bearing at the ends only. P. wolfii 



CO. Intermediate nerves of the lemma obscuio. 



f. Marginal nerves smooth; glumes narrow. P. alsodes 



