112 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 



Leaves three or four times as long as broad. 



Leaves gray or glaucous, scarcely 1.5 meters long. 

 Teeth close (1.5 to 2 cm. apart) ; margin incise(i-97. A. felina. 

 Teeth more separated or margin not incised. 

 Leaves gray-and-green -banded, often rough. 



Teeth on fleshy hummocks 98. A. subzonata. 



Teeth without such hummocks 99. A. zonata. 



Leaves not conspicuously zoned. 



Spine needle-shaped 1.00. A. gracilispina. 



Spine stout-conical. 



Leaves acuminate 101. A. melliflua. 



Leaves acute. 



Teeth on fleshy hummocks 102. A. quiotifera. 



Teeth v^athout such hummocks 103. A. crassispina. 



Leaves green or slightly gray, plicate, 2 meters long. 



104. A. tecta. 

 Leaves elongate (10 times as long as wide or longer). 

 Leaves smooth. 



lieaves green (or relatively broad if gray), extremely large. 



105. A. atrovirens. 

 Leaves gray. 



Leaves very long (over 2 meters) and narrow. Teeth small. 



106. A. mapisaga. 

 Leaves moderate. 



Leaves scarcely repand (Pacific) 107. A. schlechtendalii. 



Leaves more repand (central) 108. A. bourgaei. 



Leaves white and very large 109. A. rairabilis. 



Leaves rough. Plants very glaucous except the green scape. 



110. A, franzosini. 



II. LITTAIi]A. Flowers in a spike or spikelike cluster. 



A. Leaves not striate-ridged. 



B. Leaves neither filiferous nor with a detachable margin. 

 C. Leaves elongate, at most minutely denticulate. 

 Leaves rather fleshy, tapered from the base. 

 Leaves With slender spine; flowers withering. 

 Margin denticulate. 



Pedicels distinct 123. A. ynccaefolia. 



Pedicels on a peduncle 1*24. A. eduardi. 



Margin smooth 125. A. houghii. 



Leaves without spine; flowers drying rotate 122. A. bracteosa. 



Leaves rather stiff, oblong. 



Leaves light green, narrow (scarcely 1 cm. wide) 



120. A. dasylirioides. 



Leaves gray, broader (2 cm. wide) 121. A. intrepida. 



CC. Leaves relatively broad, at most minutely denticulate. 

 Leaves without spine. 



Leaves without spine or denticles. 



Plants with elongate trunk 126. A. attenuata. 



Plants nearly or quite acaulescent 127. A. ellemeetiana. 



Leaves without spine but denticulate 128. A. pruinosa. 



