PAX1CEAI<: 45 



13 ECHINOCHLOA Beauv. 



Panicles simple, spike-like; plant usually low 



and spreading. 1. e. colona. 



Panicles branched, plant much taller when 



mature, spreading when young. 2. E. crus-galU. 



I. Echinochloa colona (L.) A not uncommon glass in irri- 

 gated land in the southern part of the State; in the Sonoran Zones. 

 A variety having purplish bands across the leaves is var. ZOnalis. 



2. Echinochloa crus-galll (L.) Beauv. Barnv'ard Grass. 

 The species, having awns about 1 inch long is not very common but 

 the variety mutlca with awns about Vs of an inch long is a very 

 common field weed especially on fallow lands which get flooded. 

 Most common in the Lower Sonoran Zone. 



14. PASPALUM L. 



Stems rooting at the joints, panicle with two 



terminal racemes. 1. p. distichwn. 



Stems not rooting at the joints, more or less 

 erect; branches of the panicle more than 

 two. 



Splkelets on short pedicels; plant almost 

 glabrous, the slender hairs almost all con- 

 fined to the leaf margins. 2. P. ciliatifolium. 



Splkelets sessile or nearly so; plant more or 

 less villous with slender stiff hairs, es- 

 pecially on the leaves and sheaths. 3. P. Bushii. 



I. Paspalum distichum L. A common weed in the ditches 

 and on flooded land in the southern part of the State. Lower 

 Sonoran Zone. 



2. Paspalum ciliatifolium Michx. Known only from a single 

 collection near Kosweil. Probably not uncommon in the eastern part 

 of the State. 



3. Paspalum bushii Nash, a rare grass, found on the plains 

 in the northeastern part of the State. Upper Sonoran Zone. 



15. SYNTHERISMA Walt. 

 I. Syntherisma sanguinale (L.) Dulac. Crab Grass. 



Common as a field and garden weed in the warmer cultivated val- 



