POACEAE 91 



5. Panicum digitarioides Carpenter. Aquatic. Stems from stout rootstocks, 6-12 

 dm. tall or more : leaves glabrous ; blades 3 dm. long or less, 6-12 mm. wide : racemes 

 6-20, appressed, one-sided, 4-10 cm. long, the racliis barely if at all winged : spikelets in 

 pairs, the one short- the other longer-pedicelled, about 2.5 mm. long, the scales promi- 

 nently nerved, the first scale ovate, acute, the fourth scale smooth. 



In shallow water, Delaware to Florida and Texas. Spring and summer. 



6. Panicum ciltatissimum Buckl. Perennial. Stems slender, branched at the base 

 and barljed at the nodes, 2-G dm. long : leaf-sheaths pubescent ; blades 4-9 cm. long, 3-5 

 mm. wide, flat, sparingly pubescent beneath and usually long-ciliate on the margin near 

 the base : panicle 4-6 cm. long, its branches erect : spikelets about 4 mm. long, ovoid, the 

 first scale deltoid-cuneate, but little shorter than the spikelet, glabrous, the second scale 

 pubescent, the hairs near the margin very long, the third scale pubescent near the margin 

 with very long hairs. 



In low grounds, southern Texas. Spring and summer. Indian Wheat. Carpet Grass. 



7. Panicum fdscum Sw. Annual. Stems tufted, finally branching at the base and 

 often rooting at the lower nodes, glabrous, 3-8 dm. long : leaf-sheaths glabrous, pubescent ; 

 blades 2.5 dm. long or less, 8-20 mm. wide, glabrous or pul)escent : panicle 1-2 dm. long, 

 its branches ascending or nearly erect : spikelets usually borne in pairs on one side of 

 the branches on frequently bristle-bearing pedicels, brown or green, 2.5-3 mm. long, 

 broadly obovoid, turgid, glabrous, obtuse, the second and third scales with anastomosing 

 veinlets, the fourth scale transversely rugose. 



In various situations, southern Florida and Texas. Also in tropical America. Spring to fall. 



8. Panicum fasciculatum Sw. Annual. Stems 4-6 dm. tall, glabrous, branching 

 below: leaf-sheaths glabrous; blades 2 dm. long or less, 1.5-2 cm. wide, glabrous: pan- 

 icle 1-2 dm. long, its branches ascending or nearly erect : spikelets usually borne in pairs 

 on one side of the branches, green, glabrous or pubescent, oval, abruptly acuminate, about 

 4 nnn. long, the second and third scales with a few anastomosing veinlets, the fourth scale 

 transversely rugose. 



In sandy soil, Key West. Also in the West Indies. Spring to fall. 



9. Panicum Texanum Buckl. A softly pubescent annual. Stems 3-8 dm. tall, leafy, 

 often branched at the base : leaf -blades erect, lanceolate, acuminate, conmionly 1-2 dm. 

 long, 1-2 cm. wide : racemes usually 6-12, erect, one-sided, 3-8 cm. long, the rachis wing- 

 less : spikelets in pairs, 5-6 mm. long, ovate, acute, pubescent, one short- the other longer- 

 pedicelled, the pedicels bristly, the first scale more than A as long as the spikelet, ovate, 

 acute, the fourth scale transversely rugose. 



On plains and prairies, Texas. Summer and fall. Texas Millet. 



10. Panicum Chapmdnii Vasey. Glabrous or nearly so. Stems 3-6 dm. tall, 

 slender, sometimes branched below : leaf-blades 3 dm. long or less, 4-6 mm. wide, long- 

 acuminate : inflorescence 1.5-2.5 dm. long, composed of appressed one-sided racemes, the 

 lower ones 3-5 cm. long, the rachis terminating in an awn-like point : spikelets nearly 

 sessile, 2 mm. long, singly disposed in 2 rows, broadly obovoid, glabrous, the fourth scale 

 finely transversely rugose when mature. 



In sandy soil, Florida keys. Summer. 



11. Panicvmi ramis^tum Scribn. Glabrous. Stems from a stout rootstock, 2-6 

 dm. tall, simple : leaf-blades ascending, 4-12 cm. long, 2-4 mm. Avide : panicle narrow, 

 4-10 cm. long, its short branches appressed and terminating in an awn-like projection : 

 spikelets about 2.5 mm. long, the fourth scale transversely rugose. [P. .iicbspicatum Yasey, 

 not Desv. ] 



In sandy places, southern Texas. Spring and summer. 



12. Panicum Reverchonii Vasey. Glabrous. Stems from a stout rootstock. 2-4 

 dm. tall, simple : leaf-blades erect, usually involute in drying, 1-2 dm. long, 2-4 mm. 

 wide : panicle narrow, 6-12 cm. long, its short branches appressed and terminating in an 

 awn-like projection : spikelets 3.5 mm. long, glabrous, the fourth scale finely and trans- 

 versely rugose at maturity. 



On sandy plains, Texas. Spring and summer. 



13. Pantcum verrucosum ]\[uhl. Stems erect or decumbent, slender, generally 

 much branched at the base : leaf-sheaths glabrous ; blades 5-18 cm. long, 2-8 mm. wide, 

 erect or ascending, glabrous : panicle 7-30 cm. long, its lower branches 5-15 cm. long, 

 naked below : spikelets about 1.5 mm. long, elliptic, acutish. 



In moist or wet soil, Massachusetts to Florida and Louisiana. Spring to fall. 



14. Panicum brachyantlium Steud. Glabrous. Stems at first erect, finally prostrate 

 at the base and branching, and rooting at the lower nodes, sometimes 1 m. long: leaf-sheaths 

 shorter than the internodes ; blades erect or nearly so, usually 1.5 dm. long or less, 2-3 mm. 



