6 4 



6. Annual Hordeum and Annual Bromes. 



Hordeum. 



Eared. 

 Split. 



Annual Bromes. 



Earless. 

 Entire. 



Blade 



Sheath 



7. Bromus. 



Perennial. Asper^ gigametis, erectus. 



Annual or Biennial Arvensis, mollis, racemostts^ secalimis, 



sterilis, c. 

 Bromus giganteus, L., can scarcely be distinguished from 



meadow fescue by its leaves. 

 Bromus erectus, Huds., has, like annual bromes, an entire 



sheath, and an earless blade. It is the only brome specie? 



with a folded bldde. 

 Annual bromes can scarcely be distinguished from one another 



by the leaves. When annual, all the shoots are fertile ; 



in the first year of biennial species, all the shoots are 



barren : in the second year, all are fertile. 



8. The blades are folded in Koeleria, Avena pube- 

 scens, Triodia decumbens, Festuca sciuroides, and 

 Bromus erectus. 



9. The ribs are very prominent in Koeleria and 

 Festuca species. 



10. The ligule is a tuft of hair in Phragmites^ 

 Molinia, and Triodia. 



11. The rare annual genus Digitaria belongs to this 

 group. The base of the blade has a tuft of long 

 hair which is continued as a row along each margin 

 of the reddish-coloured and ribless blade. 



12. The ligule is a tuft of hair in the rare genus 

 Setaria. The blades are keeled, and when held 

 up to the light a white strip is seen along the median 

 line. 



13. The ligule is entirely absentia Echinochloa ; other- 

 wise this grass resembles Setaria. 



