Nash : The dichotomous Panicums 574 



of the sheaths, the few basal hairs of the blades, and particularly 

 in the strongly pubescent spikelets. From P. Eatoni it may be 

 distinguished by its much smaller spikelets with the first scale 

 glabrous and orbicular. 



Panicura longiligulatum 



A tufted perennial, glabrous, with the exceptions noted below. 

 Culms 4—5 dm. tall, slender, finally branching, the branches fasci- 

 culately much divided and forming dense masses at their ends ; 

 leaves 4 or 5 ; sheaths usually from one third to one half as long 

 as the internodes, minutely pubescent between the prominent 

 nerves ; ligule a ring of long erect silky hairs about 3 mm. in 

 length ; blades ascending, lanceolate, obtusely and minutely pubes- 

 cent on the lower surface, the margins serrulate and very rough, 

 the primary culm blades 2.5-3 cm. long, about 3 mm. wide, those 

 on the branches much smaller, the basal blades thick, broadly 

 lanceolate, 4—5 cm. long : panicle oval, 5—6 cm. long, considerably 

 exserted, its branches spreading, the larger ones about 3 cm. long: 

 spikelets about 1.3 mm. long and 0.8 mm. wide, oval, the outer 3 

 scales densely pubescent with spreading hairs, the first scale ovate, 

 I -nerved, about one third as long as the spikelet, the second and 

 third scales 7-nerved, about equal in length, the fourth scale yel- 

 lowish white, about 1.2 mm. long and 0.7 mm. wide. 



Collected by Dr. Geo. Vasey, at Apalachicola, Florida, in 

 1892. Its relations-hip is with P. parvispiaduni, but its more 

 slender culms, smaller blades and spikelets and the glabrous mar- 

 gins of the sheaths at once distinguish it. 



Panicum patentifolium 



A tufted purplish perennial, glabrous, with the exceptions noted 

 below. Culms erect or nearly so, 2—4 dm. tall, puberulent, 

 slender, finally much branched : leaves 2-4, rather distant ; sheaths 

 less than one half as long as the internodes, minutely pubescent, 

 especially at the apex on the margins, rather loosely embracing 

 the culm ; ligule a dense ring of hairs about 0.25 mm. long ; blades 

 widely spreading, firm, lanceolate, 2. 5—4 cm. long, 2—4 mm. wide, 

 puberulent at the very base on the upper surface, smooth on both 

 sides, rough on the margins, the basal ones similar in shape and 

 texture but larger : panicle at length considerably exserted, broadly 

 ovate, 4-6 cm. long, its axis and spreading branches puberulent, 

 the larger branches 2—3 cm. long: spikelets about 2.5 mm. long 

 and 1.3 mm. wide, the first scale orbicular, clasping, purple, at 

 least at the base, i -nerved, rounded at the apex, one half as long 



