THE MONOCOTYLEDONES 



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Fig. 2012. — Nan/us. A, Spikelet. B, Spikelet open showing sinjjlc flower. Spartina. 



C, Flower. D, Spikelet. 



nerved, awnless or awned from the back or from a sinus of the 

 two-lobed tip. The awn is generally geniculate and twisted below 

 the knee. Lodicules two. Stamens three. 



Fig. 2013. — AveiHi. A, Flower. B, Spikelet. .h^iostis. C, Spikelet. D, Flower. 



This tribe contains about thirty-eight genera, including a number of 

 fodder grasses which occur mainly in temperate regions and only in moun- 

 tainous regions in the tropics. Among the more important genera we may 

 mention Air a, Deschatnpsia, Ho/ciis, Arrhenatherum (Fig. 2014), Trisetum, 

 Avena and Koelerta, all of which occur in Britain. Arena sativa is the Oat 

 and will be considered in more detail in Volume IV under Economic 



