1918] The Grasses of Illinois 307 



leaves are much broader than in either of these species, and the white 

 spots between the veining of the sheaths is quite distinctive. 



JACKSON CO. Makanda, Glcason in 1903. johnson co. Without locality, 

 SchnecJc in 1902; Tunnel Hill, Schneck, May, 1902. 



SPRETA 



The plants belonging to this group are rather stiff and have short, 

 narrow leaves not over 8 mm. wide. They resemble the plant shown 

 in Fig. 73. The ligule is a ring of long hairs, usually 5 to 6 mm. 

 long. The plants are seldom pubescent, but the spikelets usually are 

 short pubescent. The autumnal form does not differ very widely from 

 the spring form, the extra branches being short and closely appressed 

 to the plant. 



Panicum lindheimeri Nash 



(Fig. 72) • 

 Hitchcock and Chase '10, 203. 



Vernal culms erect, rather stiff, 1 to 3 feet high, smooth or some- 

 times finely pubescent on the lower part ; lower sheaths usually with 

 fine pubescence, the upper smooth and usually about 

 half the length of the internodes; ligules often 

 4 to 5 mm. long; blades smooth on both surfaces; 

 spikelets 1.4 to 1.6 mm. long, densely pubescent. 

 Autumnal culms spreading, or often lying on the 



-n- rro -n T J grouud, brauchiug at the nodes, the branches short 

 Fig. 72. — P. Una- ^ i ^ ' 



hcimcri, spikelet and appressed to the culm, the leaves much smaller 



than the vernal form, and pointed. 



This species is very variable as to the kind and amount of 

 pubescence present. The plants are usually smooth thruout but often 

 pubescent near the base. The species has the general appearance 

 of P. diclwtomum in the vernal form, but is usually taller. It also 

 resembles a narrow-leaved plant of P. JiuacJiucae silvicola. 



ILLINOIS SPECIMENS: Without locality, Vasey. champaign co. ITrbana, 

 Seymour, June, 1880. cook co. Chicago, Nelson in 1899; Irondale, Chicago, 

 Hill, July, 1913. jackson co. Without locality, French in 1871. lake co. 

 Beach, Umbach 2242. ST. clair co. Without locality, Eggert 237. 



LANGUINOSA 



In this group the plants are usually conspicuously pubescent. The 

 blades are not over 10 mm. wide and are usually narrower. The 

 ligules are densely hairy, from 2 to 5 mm. long. The spikelets are 

 pubescent and never more than 3 mm. long. The autumnal form is 

 much branched and quite different from the spring form. The leaves 

 and panicles are considerably smaller. The species now included in 



