Memoir 10 
Plate I 
TYPES OF SPIKELETS AND BASES OF OUTER GRAINS 
1, Avena sterilis (wild form). A. the complete spikelet, with its strong awns and hairy lemmas; B, 
base of the outer grain, showing its distinct articulating surface and the remnant of the rhachilla, 
which was torn away with the persistent inner grain 
2, Arena fatua. A, the complete spikelet, with its strong awns and hairy lemmas; B, base of the 
outer grain, showing its distinct articulating surface and its rhachilla from which the inner grain easily 
separates. 
