342 American Midland Natitralist Monograph No. 7 



46. Milium L. — Wild Millet 

 M. effusum L. Moist woods; Kane Co., Vasey; Tazewell Co., 

 Brendel; probably now extinct in 111. May-July. 



47. Oryzopsis Michx. — Rice Grass 

 1. Leaves narrow, involute; spikelets (excluding the awns) 3-4 mm 



long; dry soil, rare, or probably now extinct in 111. 



O. pungens (Torr. ) Hitchc. 



1. Leaves flat, 4-15 mm wide; spikelets (excluding the awns) 6-8 



mm long. 



2. Leaves scattered along the stem, the upper sinface pubescent; 



panicle 15-30 cm long; rocky woods, rare; La Salle Co., 



McDonald in 1919, Peoria Co., Alice Heading in 1882, 



Vermilion Co., A. B. Seymour in 1884. Aug.-Sept 



- O. racemosa (Sm.) Ricker 



2. Leaves mostly basal, merely scabrous above; panicle 5-8 cm 

 long; Cook Co., Shipman m 1877 0. asperijolia Michx. 



48. Stipa L. — Spear Grass 



1. Awn 10-25 cm long; glumes 1.5-4 cm long. 



2. Glumes 1.5-2.8 cm long; grain 1-1.5 cm long; Winnebago Co., 



E. W. & G. B. Fell S. comata Trin. & Rupr. 



2. Glumes 2.8-4 cm long; grain 2-3 cm long; sandy ground or 

 prairie soil, locally in the n. half of 111. May-Jime. Porcu- 

 pine Grass S. spartea Trin. 



1. Awn 2-3 cm long; lemma 5-6 mm long; glimies 7-10 mm long; 

 Kane Co., Benke in 1916; McHenry Co., V. H. Chase in 1948. 

 Green Needlegrass ..S. viridula Trin. 



49. Aristida L. — Three-awned Grass 



1. Awns jointed to the lemma. 



2. Awns united in a spiral column 6-15 mm or more in length; 

 sandy soil in the n. half of 111. Aug.-Sept A tuberculosa Nutt. 



2. Awn-column about 2 mm long; sandy soil, not common; Cass, 



Mason, and Morgan counties A. desmantlia Trin. & Rupr. 



1 . Awns distinct, not jointed to the lemma. 



3. Central awn much longer than the lateral awns, these erect. 

 4. Central awn spirally coiled at base. 



5. Second glume 7-9 mm long, ecjualling or slightly longer 

 than the first; roadsides and fields, chiefly in central and 

 s. 111. Au2f.-Oct .-A. dichotoma Michx. 



O 



5. Second olume 10-15 mm lono-, much lonoer than the first. 

 6. Lateral awns 1-2 mm long, straight, erect; dry ground, 



not common. Sept. -Oct A. curtissii (A. Gray) Nash 



6. Lateral awns 2-7 mm long, spreading; dry ground, scat- 

 tered A. hasiramea Engelm. 



4. Central awn not coiled, but with a semicircular bend at 

 base. 



