FLORA OF THE DISTRICT OF COLUMBIA. 77 



Spikolets less than 2 mm. long. 

 Culms crisp-puberulent 37. P. columbianum. 



Culms glabrous. 

 Nodes glabrous; culms delicate, sparingly branching. 



40. P. ensifolium. 

 Nodes bearded; culms slender but not delicate, very freely branching. 



19. P. microcarpon. 



1. Panicum dichotomiflorum Michx. 



Common in moist ground and embankments; a weed in cultivated soil. Aug.-Sept. 

 Eastern and middle states. (P. proli/erum of Ward's Flora.) 



2. Panicum flexile (Gattinger) Scribn. 



Moist sandy soil; infrequent in our region. Sept. Eastern and middle states. 



3. Panicum gattingeri Nash. 



Open and waste ground; frequent; a weed in cultivated soil. Sept. Eastern and 

 middle states. 



4. Panicum philadelphicum Bernh. 



Open sandy or argillaceous soil; common. Aug.-Sept. Eastern and middle states. 



5. Panicum capillare L. Witch grass. 

 Open ground, fields, and waste places; common. Sept. A weed in cultivated soil. 



Atlantic Coast to the Rocky Mts. 



6. Panicum miliaceum L. Hog millet. Broomcorn millet. 

 A weed in waste ground; rare. July-Aug. Escaped from cultivation in the north- 

 eastern and middle states; native of Eur. 



7. Panicum virgatum L. 



Open moist ground and open woods; frequent, especially near the Potomac. July- 

 Aug. Atlantic Coast to the Rocky Mts. 

 7a. Panicum virgatum cubense Griseb. 



Boggy pine woods; infrequent; College Park and Beltsville. July-Aug. Atlantic 

 Coastal Plain. 



8. Panicum agrostoides Spreng. 



Wet meadows and swales; infrequent. Aug. Eastern U. S. 



9. Panicum condensum Nash. 



Swales near the Potomac below Washington; rare. Sept.-Oct. Atlantic Coastal 

 Plain. 



10. Panicum stipitatum Nash. 



Wet meadows and swales near the Eastern Branch and Potomac; frequent. Sept. 

 Eastern U. S. 



11. Panicum longifolium Ton*. 



Moist sandy or gravelly ground in the valley of the Eastern Branch; infrequent. 

 Aug. Atlantic and Gulf states. 



12. Panicum anceps Michx. 



Moist open ground or open woods; common. Aug. Eastern U.S. 



13. Panicum verrucosum Muhl. 



Wet sandy woods or shaded ditches; frequent from Takoma Park eastward. Aug.- 

 Sept. Eastern and southern states and in northern Ind. 



14. Panicum depauperatum Muhl. 

 Sterile woods; frequent. Eastern U. S. 



15. Panicum linearifolium Scribn. 



Dry woods along the north side of the Potomac; frequent. Eastern U. S. 



16. Panicum werneri Scribn. 



Pine woods; near Paint Creek. Me. to Mo. and Md. 



17. Panicum xalapense H. B. K. 



Rich alluvial woods or open ground along the Potomac from District Line to Great 

 Falls; frequent. Southern states, north to Md. (P. laxifiorum of Britt. & Brown, 

 Illustr. Fl.) 



