56 MISSOURI BOTANICAL GARDEN. 
first flowers of Y. flaccida, 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 to 
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. raprosA (Engelmann) Trelease, Rept. Mo. Bot. Gard. 
3: 163. (1892). 
Y. angustifolia radiosa Engelmann, Bot. King. 496. (1871). 
Y¥. angustifolia elata Engelmann, Trans. Acad. St. Louis. 8: 50, 51. 
(1873). — Watson, Proc. Amer. Acad. 143 253. 
Y. elata Engelmann, Bot. Gaz. 7:17. (1882). — Coulter, Contr. U. 8S. 
Natl. Herb. 2: 437. — Garden. 86:3 573.— Gard. & Forest. 2: 568. 
jf. 146. 93813. — Rept. Mo. Bot. Gard. 8: 164. pl. 9. 4: 201. pl. 
10,15, 22.— Bot. Mag. iii. 55. pl. 7650. 
Y. constricta Baker, Journ. Linn. Soc. Bot. 18 ; 229. — Sargent, Silva. 
103: 27. pl. 504.—In part. 
Y. angustifolia Havard, Proc. U. 8. 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 10> 12 to 15 mm. — Plates 21, f. 2. 22. 83, f. 5. 
86, f.1. 
Southern Arizona to the Rio Grande, as far as the big 
bend, and south to about the city of Chihuahua. — Plate 
Sef. 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 
