3fi0 



and fruit, from the common sessile Yucca filamentosa of our gardens to 

 the arboreal forms, like brerifoUa of the Mojave Desert and fiUfera of 

 Mexico. My remarks will be based chiefly ou Yucca Jilamentosa, which 

 is indigenous to the Southeastern States and is cultivated beyond its 

 natural range, under a number of horticultural variety names, in our 

 gardens. 



An examination of the flower will show atonce the peculiarities which 



I have s.lluded to as characteristic of the 

 genus. The stamens or filaments are bent 

 away from the stigma and do not reach 

 more than two thirds the length of the 

 pistil, the stigmal opening being at the 

 tip of the prolonged style and nowhere 

 within reach of the stamens, while the 

 pollen either remains attached to the open 

 and withered anthers or falls in diflerent 

 sized lumps on the underside of the peri 

 anth. It can not be introduced into the 

 stigmatic tube without artificial aid, and 

 the plant depends absolutely on the little 

 white moth belonging to the Tineina and 

 known as Promtha yuccaseUa Riley (Fig. 

 58). 



Fig. 58.— Pronuba yuccasella: a. lar- 

 va; 6, ? moth with closed wing; c, do. 

 with wings expanded, natural size; (i, 

 side view of larval joint; e. head of 

 lar-va, beneath; /, do. above; g, tho- 

 racic leg of same; 7t, maxilla; i, man 

 dible ; j, spinneret and labial palpi ; 

 k, antenna, enlarged. 



STR[TCTUBAL CHARACTERISTICS OF PRONUBA. 



Upon a superficial view, this little moth shows nothing very pecul- 

 iar. The general coloration is white, the primaries being purely white 

 on the upper surface, so that when at rest in the half-open flowers of 



Fig. 59. — Pronuba yuccasella: Generic characters — a, side view of head and neck of female de- 

 nuded, showing how the collected load of pollen (1) is held by the tentacles (2) ; 6, maxOlary tentacle 

 and palpus; c, an enlarged spine ; d, ])alpus separated; e, scale from front wing; /, front log; g, palpus; 

 A, i, front and hind wings denuded ; j, anal joint of female with ovipositor. 



