itE. a. iEKTflAM ON tiRAMllH-Ejtl. 11 



globe, but often only as an introduced weed. One at least of the 

 glumes of the lowest pair is the largest of the spikelet, as in 

 PAalaris; those of the second pair, though small and without 

 flowers, have a dorsal awn. The panicle is usually cylindrical 

 and spikelike. 



6. HiEEOOHLOA, Giael.{Savastana,8akraxik,Disarrenum,Tjah\l]., 

 Torresia, Euiz and Pav.), about eight species from the colder or 

 mountain regions both of the northern and the southern hemi- 

 spheres, is usually referred to Avenaces3 next to JSoleus ; but it 

 appears to me to be much nearer to Anthomanthum, from which 

 it dift'ers in its looser paniculate inflorescence, and in the glumes 

 of the second pair being but little smaller than the lower ones, 

 and frequently, but not always, enclosing each a male flower. 

 Ataxia, Br., one or two Asiatic and two South-African species, 

 forms a section of Hierochloa, differing slightly from the typical 

 form in the glumes of each pair being more unequal, the lower 

 one only of the second pair (rarely both) having a male flower. 

 A. mecdcaiia, Rupr., seems to connect the two sections. 



Tribe VIII. AeEOSTBiE. 

 The large tribe Agrostese is one of the most diificult to circum- 

 scribe satisfactorily, or to divide into definite genera. We have 

 taken it nearly in the sense given to it by Trinius, so as to in- 

 clude the StipesB, of which other botanists make a distinct tribe ; 

 and we have adopted thirty-seven genera, a number which some 

 would extend to above eighty, whilst others might reduce it to 

 about thirty. Their general character is to have a single flower 

 in each spikelet, either apparently terminal as in Panicacese, or 

 with a slight bristle-like continuation of the rhachilla beyobd it; 

 and from these PanicacesB they are constantly distinguished by 

 the pair of empty glumes persistent below the articulation of the 

 rhachilla, without any empty glume or male flower intervening 

 between the articulation and the flowering glume. The single 

 flower in the spikelet, which separates the tribe from the follow- 

 ing ones, is not so positive a character, as it occurs also in one 

 genus of AvenesB, in a few genera of ChloridesB, and occasionally 

 in a few exceptional species of some gene]-a of Festucese, which 

 cannot well, from inflorescence or other accessory characters, be 

 included in Agrostete. There are also two species of Sporololus 

 which approach the Isanthe® in having frequently two flowers ; 

 and in Coleanthus the lower empty glumes are entirfily deficient. 



LIIW. JOTJEK.— BOTATfT, TOi. XIX. H 



