56 MISSOURI BOTANICAL GARDEN. 



first flowers of Y. jlaccida, which they closely resemble, and 

 at the end of the flowering period of Y. glauca and its va- 

 riety stricta. It is hard to see how this plant can be 

 separated from Y. constricta. What appears to be the same 

 has been collected by Dr. Kleinschmidt at Mt. Kiowa, Okl., 

 and the character of the intervening country is such as to 

 make its extension probable from southwestern Kansas ta 

 the Pecos river of Texas, while Professor Bray's photo- 

 graph referred to above shows it to be a characteristic 

 plant of the staked plains. 



Y. RADIOSA (Engelmann) Trelease, Rept. Mo. Bot. Gard. 



3: 103. (1892). 



Y. angustifolia radiosa Engelmann, Bot. King. 496. (1871). 

 Y. angustifolia data Engelmann, Trans. Acad. St. Louis. 3 : 50, 51. 



(1873). Watson, Proc. Amer. Acad. 14 : 253. 

 F. elata Engelmann, Bot. Gaz. 7 : 17. (1882). Coulter, Contr. U. S. 



Natl. Herb. 2 : 437. Garden. 86: 573. Gard. & Forest. 2: 568. 



/. 146. 9 : 313. Rept. Mo. Bot. Gard. 3 : 164. pi. 9. 4 : 201. pi- 



10,15, 22. Bot. Mag. iii. 55. pi. 7650. 

 Y. constricta Baker, Journ. Linn. Soc. Bot. 18 : 229. Sargent, Silva. 



10:27. pi. 504. In part. 

 Y. angustifolia Havard, Proc. U. S. Natl. Mus. 8 : 470. 



Caulescent, the larger trees reaching a height of 5 to 7 m., simple or 

 with a few short branches at top. Leaves pallid, rather rigidly diver- 

 gent, long, 3 to 10 or rarely 13 mm. wide, white-margined and soon finely 

 and copiously filiferous. Inflorescence large, panicled on a long ex- 

 serted peduncle, glabrous. Flowers white, bell-shaped, with lanceolate 

 attenuate segments : style white, oblong. Capsule oblong, smooth, not 

 or rarely constricted, with ribless convex valves, straw-colored: seeds 

 rather dull, 8 to 10X 12 to 15 mm. Plates 21, f. 2. 22. 83, f. 5. 

 S6,f.l. 



Southern Arizona to the Rio Grande, as far as the big 

 bend, and south to about the city of Chihuahua. Plate 

 93, f. 1. 



In describing the Yuccas for Watson's Botany of the 

 Fortieth Parallel, Dr. Engelmann characterized an arbores- 

 cent plant with large panicles and lanceolate petals under 



