16 GKAMINEAE 



1. S. Halepense (L. ) Pers. Johnson-grass. 3°-5° high: leaves 

 long and l)roa(l : panicle often 1° long : outer glumes of spikelets pubes- 

 cent. — Frequently adventized along railrojids. — June-September. 



5. PASPALUM L. 



Rpikelets in 2-4 rows in one-sided spikes, awnless, planoconvex, very 

 shortly pedicelled. Glumes three. Spike one to many. 



Rachis winged, spikes 20 or more. 1. P. mucrondtuDi. 

 Eachis not winged, spikes one to three. 



Culms erect. 2. P. Biishii. 



Culms reclining. 3. P. Muhlenhergii. 



1. P. mucronatiim Muhl. Annual : culms decumbent or ascending : 

 rachis of spikes broadly winged, incurved, partly inclosing the spikelets, 

 tapering to an acute point : spikelets in two rows, pubescent, rather 

 pointed. — Along Sni-a-bar Creek about three miles south of Grain Valley. 

 August-October. 



2. P. Bushii Nash. Culms 2°-3° high, erect : leaves densely short 

 soft-pubescent on both sides : racemes in twos or threes : spikelets V long, 

 the empty scales pubescent. — Occasional in sandy grounds, especially in 

 the Missouri bottoms. Often appears as if adventized. August-October. 



3. P. Muhlenbergil Nash. Resembles the last but culms reclining : 

 leaves sparsely pubescent with long hairs : racemes solitary or in twos and 

 spikelets glabrous. — In a field near Eoanoke, Kan.sas City. August- 

 October. 



6. ERIOCHLOA H B.K. 



Perennial grasses with llowers in panicled spikes. Spikelets with a 

 callus at base. Glumes three, the two outer acute and membranous, the 

 shorter inner one obtuse and hardened. 



1. E. punctata ( L. ) O. Hamilt. Dotted Millkt. Ascending culms 

 \\° high, bearing 4-15 spikes, the latter 1^-2' long: spikelets hairy, about 

 2''^ long. — Occasional in the railroad yards at Shcflield. July-August. 



7. SYNTHERISMA Walt. 

 Annual grasses with flowers in spikes, approximate at the summit of 

 the culm. Rpikelet awnless and pointless with four scales, the lowest 

 minute or wanting. 



Rachis three-angled, not winged. 1. S.flliformia. 

 Rachis flat, winged. 



Sheaths and leaves gkibrous. 2. S. linearis. 



Sheutlis and leaves more or less pubescent. 3. <S. mnguinah's. 



1. S. filiformls (L. ) Nash. Slender Crab-grass. Erect slender 

 culms l°-3° high : spikes 2-8, erect, filiform, 2'-'^ long : spikelets J" 

 long : lower glumes wanting. — Occasionally occurs in dry soil throughout 

 the southern part. August-October. 



