32 GRAMINEAE 



44. DACTYLOCTENIUM Willd. 

 1. Dactyloctenium Aegyptium (L.) Willd. Egyptian Grass. 

 (Man. p. 124 ; I. V.f. 416.) In waste places and cult, ground, southern 

 N. Y. and Va. to III. and Cal., Fla. and Mex. Pennsylvania ; Dela- 

 ware ; Philadelphia. 



45. PHRAGMITES Trin. 

 1. Phragmites Phragmites (L. ) Karst. Reed. (Man. p. 126; I. F. 

 /. 420.) In swamps nearly throughout the U. S., extending north to N. 

 S., Man. and B. C. Also in Europe and Asia. — Pennsylvania : Dela- 

 ware ; Chester ; Erie, Presque Isle ; Philadelphia, Point Breeze. 



46. TRIDENS R. & S. 



1. Tridens seslerioldes (Michx. ) Nash. Tall Red-Top. (Man. p. 

 126 ; I. F.y". -J.21. ) In fields, N. Y. to Kans., Fla. and Tex. — Pennsylvania : 

 Delaware; Chester; Bucks; Luzerne; Northampton; Lan- 

 caster ; Huntingdon ; Philadelphia ; York ; Franklin. 



47. TRIPLASIS Beauv. 



1. Triplasis purpurea (Walt.) Chapm. Sand-grass. (Man. p. 127; 

 I. F. /. 424.) In sand, especially on sea beaches, Me. to Tex. and along 

 the Great Lakes. Also from Neb. to N. Mex. — Pennsylvania : EriE, 

 Presque Isle. 



48. ERAGROSTIS Beauv. 



Stems not creeping : flowers perfect. 

 Annuals. 

 Spikelets 2-5-flowered. 

 Pedicels and branches of the panicle short : stems usually branched 



above. i. E. Frankii. 



Pedicels and branches of the diffuse panicle long and capillary : stems 

 branched only at the base. 2. E. capillaris. 



Spikelets more than 5-flowered. 

 Spikelets 1.5 mm. wide or less : palets remaining attached to the contin- 

 uous rachis for some time after the flowering scales have fallen. 

 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 exceeding 2 mm. wide : palets falling with the flowering 

 scales and the intemodes of the rachis. 

 Spikelets 2 mm. wide : lower flowering scales about 1.5 mm. long. 



5. E. Eragrostis. 

 Spikelets 2.5-3 mm. wide : lower flowering scales 2-2.5 mm. long. 



6. E. major. 

 Perennials. 7. E. pectinacea. 



Stems creeping, rooting at the nodes. 8. E. hypnoides. 



1. Eragrostis Frankii Steud. Frank's Eragrostis. (Man. p. 130; 

 I. F.y". 42g.) In moist places, N. Y. to Minn., Miss, and Kans. — Penn- 

 sylvania : Chester ; Lancaster ; Monroe ; Northampton. 



