GRAMINEAE. 1 29 



qual, shorter than the spikelet ; flowering scales membranous, rounded on the 

 back, 3-nerved; palets scarcely shorter than the scales, obtuse, 2-keeled. Stamens 

 3. Styles short. Stigmas short, plumose. Grain oblong, free, enclosed in the 

 scale and palet. [Name in honor of Joh. Ignaz Molina, Chilian missionary and 

 naturalist.] A monotypic genus of Europe and Asia. 



I. Molinia coerulea (L.) Moench. MOLINIA. (I. F. f. 427.) Culms 3-10 dm. 

 tall, erect, simple, smooth and glabrous. Sheaths overlapping, and confined to the 

 lower part of the culm, smooth and glabrous; leaves 1-3 dm. long or more, 

 2-6 mm. wide, erect, acuminate, smooth beneath, slightly scabrous above; panicle 

 7.5-25 cm. in length, green or purple, the branches usually erect, 2.5-10 cm. long: 

 spikelets 2-4-flowered, 5-8 mm. long; empty scales acute, unequal; flowering 

 scales about 4 mm. long, 3-nerved, obtuse. Introduced on ballast and into waste 

 places, Me. to N. Y. Adventive from Europe. Aug. -Sept. 



74. RHOMBOLYTRUM Link. 



Perennial grasses, with usually flat leaves, and a narrow contracted spike-like 

 panicle. Spikelets numerous. Scales several, the outer two empty ones I -nerved, 

 the flowering scales broad, rounded at the apex, 3-nerved, the nerves glabrous, 

 the lateral ones vanishing below the margin, the miclnerve at the margin or 

 sometimes excurrent as a short tip, the callus pilose; palet 2-keeled. Stamens 3. 

 Styles short, distinct. Stigmas plumose. Grain free, enclosed in the scale. 

 [Greek, in reference to the round flowering scales.] Species 4 or 5, natives of 

 warm or tropical countries. (Sieglingia Bernh. in part.) 



i. Rhombolytrum albescens (Vasey) Nash. (I. F. f. 422a.) Culms tufted, 

 3-5 dm. tall, the sterile shoots one-half as long as the culm or more. Leaves 

 smooth beneath, roughish above, acuminate, 6.25-27.5 cm. long, 2-4 mm. wide; 

 panicle dense and contracted, white, 6.25-12.5 cm. long, 6-18 mm. broad, its 

 branches erect or ascending, 2.5 cm. or less long; spikelets 7-ii-flowered, 4-5 mm. 

 long, the empty scales white, i-nerved, about equal; flowering scales about 3 mm. 

 long, 3-nerved, the lateral nerves vanishing below the apex, the midnerve excurrent 

 in a short scabrous point. Prairies, Kans. to Tex. Aug.-Sept. (Sieglingia albescens 

 (Vasey) Kuntze.) 



75. ERAGROSTIS Beauv. (See Appendix.) 



Annual or perennial grasses, rarely dioecious, from a few inches to several feet 

 in height, the spikelets in contracted or open panicles. Spikelets 2-many -flowered, 

 more or less flattened. Two lower scales empty, unequal, shorter than the flower- 

 ing ones, keeled, I -nerved, or the second 3-nerved ; flowering scales membranous, 

 keeled, 3-nerved ; palets shorter than the scales, prominently 2-nerved or 2-keeled, 

 usually persisting on the rachilla after the fruiting scale has fallen. Stamens 2 or 

 3. Styles distinct, short. Stigmas plumose. Grain free, loosely enclosed in the 

 scale and palet. [Greek etymology doubtful, perhaps signifying a low grass, or 

 Love-grass, an occasional English name.] A genus of about 100 species, widely 

 distributed throughout all warm and temperate countries. Besides the following, 

 some 15 others occur in the southern and western parts of N. Am. 



Culms often decumbent at the base and generally much branched, 4.5 dm. tall or less ; 



usually annuals. 

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



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



and capillary. i. E. capillaris. 



Culms branched above the base ; pedicels and branches of the panicle short. 



2. E. Frankii. 



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

 Spikelets 1.5 mm. wide or less. 



Flowering scales thin, usually bright purplish, the lateral nerves faint or 



wanting ; spikelets about i mm. wide. 3. E. pilosa. 



Flowering scales firm, usually dull purple or green, the lateral nerves very 



prominent; spikelets about 1.5 mm. wide. 4. E. Purshii. 



Spikelets 2 mm. wide or more. 



Lower flowering scales about 1.5 mm. long ; spikelets 2 mm. wide. 



5. E, Eragrostis. 

 Lower flowering scales 2-2.5 mm - long; spikelets 2.5-3 mm - wide. 



6. E. major. 



