Memoir 10 
Plate II 
TYPES OF SPIKELETS AND BASES OF OUTER GRAINS 
1, Arena sterilis (cultivated form). A, the complete spikelet, with its glabrous lemmas and 
reduced awns; B, base of the outer grain, showing its evident articulating surface and the remnant 
of the rhachilla, which was torn away with the persistent inner grain 
2, Avena sativa. A, the complete spikelet, with its glabrous lemmas and reduced awns; B, base 
of the outer grain, showing its non-articulate surface and its rhachilla from which the inner grain 
easily separates 
