VIl] FLORAL CHARACTERS 105 



{Catahrosa), and the presence of two, three, or more flowers in 

 the considerably larger spikelets of all, easily distinguish them. 



The rare grasses Leersia, with two glumes and no palese, and 

 Oastridium, with curiously bullate bases to the glumes, also come 

 into this group with one-flowered spikelets, but their characters 

 must be studied with the flora. The same remark applies to species 

 of Panicum, Cynodon, Spartina and other aliens, occasionally 

 met with. 



II. Grasses with at least two flowers — of which 



ONE MAY BE IMPERFECT — IN THE SPIKELET. 



A. Only one perfect flower, the other staminate 

 only or altogether rudimentary. Inflorescence 

 a loose or racemous panicle. 



In Hordeum sylvaticum the two lateral spikelets occasionally 

 conform to this heading (see p. 100), and the same is said to be 

 the case sometimes in Aira (see p. 104). The rudiments are 

 extremely minute, however, and hardly suffice to justify the removal 

 of these grasses to this group. 



In one or two species of Aira the panicle may be somewhat 

 contracted and tuft-like. 



The very rare Hierochloe has one perfect flower, and two lower 

 staminate ones in each spikelet. 



(a) A shade-grass found in woods. Awnless. One 

 flower perfect, the other (upper) reduced to a 

 small stalked knob. Inflorescence racemous. 



Melica uniflora, L. 



The much rarer M. nutans has two perfect flowers and a similar 

 rudiment (see note, p. 104). 



(6) Grasses of open situations, spikelets with awns. 

 The reduced flower staminate. 



