224 GRASSES OF IOWA. 



General. Great Britain, Germany, northern Europe and Asia, 

 the Himalayas to Africa, temperate South America, Australia and New- 

 Zealand. 



6. ERAGROSTIS. 



Eragrostis Host. Ic. Gram. 4: 14. 1809. Bentham and Hooker. 

 Gen. PI. 3: 1186. Hackel in Engler and Prantl. Nat. Pflanz. Fam. II 

 2: 69. f 79. Scribner. Bull. U. S. Dept. Agr. Div. Agros. 20: 134. f. 

 103. (Rev. ed.) 



Poa in part. Endlicher Gen. PI. 98. 



Macroblepharus Philippi. L. 29: 100. 1855. 



Harpachne Hochst. A. Rich. PI. Abyssin. 2: 431. 1851. 



Coelachyrum Nees. L. 16: 221. 1842. 



Spikelets two to seventy-flowered, nearly as in Poa, except that the 

 flowering glume is but three (rarely one) nerved, not webby-haired at 

 the base, and is deciduous; palet persistent on the rachis after the rest of 

 the flower has fallen. Culms often branching. Leaves linear, frequently 

 involute, and the ligule or throat of the sheath bearded with Ions, vil- 

 lous hairs. Panicle various. (Name from two Greek words for spring 

 and grass. 



Bentham & Hooker recognize too species; Hackel the same num- 

 ber; Beal lists 28, including varieties, in North America. The genus 



-mopolitan, found chiefly in the tropics. 



KEY TO THE SPECIES OP ERAGROSTIS. 



Culms prostrate and creeping, flowers imperfectly dioecious. is . hypnoides. 1 . 

 Culms usually diffusely spreading, ascending (or erect in E. capillaris), 

 much branched, 4.5 dm. tall or less, usually annual. 

 Spikelets 2-5-flowered, 2-3 mm. long. 



Culms branched only at the very base; pedicels and panicle branches 



long and capillary E. capillaris."-. 



Culms branched above the base; pedicels and panicle branches 



short E . Frankii . 3 . 



Spikelets 5 to many-flowered, 3-16 mm. long. 



Spikelets 3 mm. wide, lower flowering glumes over 2 mm. long, 

 plant strong-scented from button-shaped glands on leaves and 



glumes E. major.".* 



Spikelets about 1 .5 mm . wide, lower flowering glumes 1.5. mm. 



long, scentless -E. Purskii. 6 



Culms erect, simple, panicles very large, 1 foot or more long. 



Branches of the panicle widely spreading, lower flowering glumes less 



than 2 mm. long E. pectinacea.K 



Branches of the panicle erect or ascending, lower flowering glumes 2.5- 

 3 mm. long E. trichod.es} '. 



♦Spikelets about 2 mm. wide, scentless, occasionally cultivated in Iowa. 



r — E. Mrxicaiui . *-a. 



