11 



Davis. 



Mature plants. 0'8 — 1 m. liigli, few or no 



long side branches from the rosettes in 



sharp contrast to the parents (Fig. 12). 



Tips of branches generally straight 



(patroclinous). 



Mature plants. 11 — 1"2 m. high, no long 

 side branches from the rosettes in sharp 

 contrast to the parents (Fig. 13). 



Tips of branches frequently nutant 

 (patroclinous). 



Fig. 8. Inflorescence of biennis. Sliowing younger buds projecting beyond the 



bracts which are relatively shorter than in muriciita; large flowers. At the left 



is a leaf from near the base of tlie main stem, its margin obscurely serrate. 



Contrast with Fig. 9, muricata. 



Foliage. Leaves broadly-elliptical and 

 almost plane as in biennis (patroclinous), 

 but showing evidence of a blend in being 



Foliage. Leaves narrow-elliptical and revo- 

 lute or keeled as in muricata (patro- 

 clinous), but sliowing evidence of a blend 



