HITCHCOCK GRASSES OF CUBA. 215 



Panicle small and few-fiowered, usually 

 about 5 cm. long; blades usually 5 



to 8 mm. wide .12. P. divaricatum. 



Stems herbaceous. 



Fruit transversely rugose 25. P. maximum. 



Fruit smooth. (See continuation 1.) ' 

 (Continuation 1.) 

 Plants forming a rosette of basal leaves in autumn ; early culms 

 simple, with terminal, exserted, many-flowered, spreading 

 panicles ; freely branching after maturity of primary panicle, 

 and bearing numerous reduced panicles more or less in- 

 cluded in the sheaths. (Dichotomum group.) 



Ligule a ring of hairs, 1 mm. or more long; spikelets pu- 

 bescent, 1 to 1.5 mm. long. 



Spikelets hardly 1 mm. long; foliage minutely pubes- 

 cent, not velvety 48. P. wrightianum. 



Spikelets 1.5 mm. long. 



Foliage smooth or minutely puberulent 24. P. leucothrix. 



Foliage velvety 1. P. acuminatum. 



Ligule inconspicuous. 



Autumnal state a fiat mat or rosette of soft leaves; 

 blades ciliate; spikelets 1.5 to 2mm. long, glabrous. 



Blades pilose on the surface 41. P. strigosum. 



Blades glabrous on the surface 33. P. polycaulon. 



Autumnal state erect or spreading. 

 Sheaths velvety or pilose. 



Vernal culms 1 meter or more tall, a viscid 

 ring below each node; primary panicles 10 

 to 20 cm. long; autumnal blades, 5 mm. 



or more wide 37 . P. scoparium. 



Vernal culms 20 to 40 cm. tall; primary pan- 

 icles 2 to 6 cm. long; autumnal blades 1 to 



2 mm. wide 6. P . chrysopsidifolium. 



Sheaths not velvety nor pilose. 



Culms wiry, minutely crisp-puberulent; 

 spikelets pyriform-turgid. 



Spikelets 1.5 mm. long 31. P. pauciciliatum. 



Spikelets 2 mm. long 22. P. lancearium. 



Culms glabrous, oronlylowermiostinternodes 

 pubescent. 



Spikelets glabrous, 1.6 mm. long 7. P. caerulescens . 



Spikelets pubescent. 



Nodes bearded; spikelets 2 mm. 



long 28. P. nitiduTn. 



Nodes glabrous or pubescent, not 

 bearded. 

 Blades long and narrow, autum- 

 nal blades in volute; spikelets 

 papillose. 



Spikelets 2 mm. long, blunt -27. P. neuranthum. 

 Spikelets about 3.5 mm. 



long, pointed 16 . P. fusiforTne. 



Blades not elongated , autumnal 

 blades flat; spikelets not pap- 

 illose. 



