30 PANICACE^. 



Third glume flat, 2-iierve(l, the fourth compressed, 3-nerved. 

 Lodicules 2, truncate, many-nerved. Bentham in Flora Aus- 

 tral ie/isis remarks that " RotthceUia was originally founded by the 

 younger Linnaeus on five species which are now separated into as 

 many genera. Brown's proposed plan to restrict the name to 

 R. exaUata and allied species since added has now been generally 

 adopted." 



These grasses are mostly tall perennials, with flat or compressed 

 leaf-blades. Spikes terminal and lateral. Species about 23, ex- 

 tending over tropical Asia, Africa, and 4 in America. 



The characters of this genus have been very differently restricted 

 by different botanists. I have followed E. Hackel, and included 

 Hemartliria R. Br. in this genus. 



On this subject Bentham says: " Hemarthria is separated 

 from RotthceUia chiefly on account of the flattened and less dis- 

 tinctly articulated rachis and the curious way in which the stipes 

 of the sterile spikelet is adnate to the rachis." 

 a. First glumes of the sessile spikelet 



Transversely rugose 1 



'* and vertically rugose 2 



Unequally pitted 3 



a. First glume of the sessile spikelet 



Xeither rugose nor pitted 4 



1. M. rugosa (Ohapm.) Kuntze, Rev. Gen. PI. 780 (1891). 



R. rugosa Ohapm. Hack, in D. C. Monog. Phan. 6 : 308 (1889). 

 R. rugosa Chapm. Fl. S. States, 579 (1860), not Nutt. 



Culms robust, compressed, 40-90 cm. high. Lower sheaths 

 compressed, equitant; ligule very short, truncate; lower blades 

 20-60 cm. long, 2-5 mm. wide; the upper about 4 mm. long. 

 Spikes terminal and lateral, 3-5 cm. long, 2-5 mm. diam., often 

 partly included in the sheaths. Sessile spikelets about as long 

 as the joints of the rachis. In the sessile spikelets, first glume 4-5 

 mm. long, including the spongy base, ovate, flat, 2-keeled, bifid. 

 6-8-nerved, with two or more regular spongy ridges passing more or 

 less transversely; second glume 3.5-4 mm. long; third 3.5 mm. 

 long, 2-nerved; fourth broad ovate, obtuse, 3 mm. or less in length. 



