152 



THE TRUE GRASSES. 



p. 261 (EremocMoe S. Wats.). Low, branched grasses, 



with crowded, involute leaves ; spikes few, in capitate 



panicles ; flowering glumes very hairy. 



Species two, upon the high western plateaux of North 



America. 



219. (201) Triodia Brown. Panicle usually open ; 



flowering glume rounded on the back (at least below), 

 coriaceous or chartaceous, often 

 hairy on the callus and margins. 

 Perennial grasses with narrow rigid 

 leaves and variable habit. 



Species twenty-six, throughout 

 the temperate zones, a few in tropi- 

 cal America. 



Sec. I. Isotria. Flowering glume 

 three-parted almost to the middle. 

 Tr. pungens Brown, and the related 

 Tr. Mitchelli, Tr. Cunning Jiamii, and 

 Tr. irritans Brown, belonging to 

 the following Sec., are character- 

 ized by their rigid, involute, finely- 

 pointed, and often sticky leaves ; 

 they cover, often exclusively, large 

 areas of the deserts and elevated 

 plains of the interior of Australia, 

 and are known to the colonists and 

 to travellers as "Spinifex" (not to 

 be confounded with No. 76), and are 

 very troublesome. 

 Sec. II. Sieglingia Bernhardi (as a genus). Flower- 



ing glume with three short, rather obtuse teeth. Triodia 



decujnbens Beauv. (Fig. 77) in Europe. 



Sec. III. RTiombolytrum Link (as a genus). Flower- 



ing glume shortly two-toothed, sometimes entire. In 



North and South America. ( T. filiformis Nees, T. al- 



bescens Munro, etc.) 



Sec. IV. Tricuspis Beauv. (as a genus), ( Windsoria 



Nutt., Tridens B. <fe S.). Flowering glume usually entire, 



but with the three nerves extending into three short awns 





