80 MISSOURI BOTANICAL GARDEN. 
Y. FLEXILIS ENSIFOLIA (Groenland) Baker, Journ. Linn. 
Soc. Bot. 18 : 224. (1880). 
Y. ensifolia Groenland, Rev. Hort. 1859: 433. /. 729.— Baker, Gard. 
Chron. 1870: 217. Ref. Bot. 5. pl. 378.— Engelmann, Trans. 
Acad. St. Louis. 8: 41.— Hemsley, Garden. 8 : 134. f. 
Y. Eylesit Hort. 
Taller (1 to 1.5 m.) with less recurving, soon pale green, somewhat 
concave, entire leaves. 
Y. flexilis Hildrethi Trelease. 
Differs from f. ensifolia chiefly in having its frequently somewhat fal- 
cate leaves usually finely filiferous in age.— Plate 41, f. 2. 
Cultivated, from unrecorded source, and escaped, at the 
place of Mr. J. A. Hildreth, at St. Augustine, Fla., where 
it is said to bloom through the winter and where the spec- 
cimen photographed was observed in flower at the end of 
May, simultaneously with Y. aloifolia, — though it has 
never been known to set fruit. 
Y. flexilis tortulata (Baker) Trelease. 
Y. tortulata Baker, Gard. Chron. 1870: 1122.— Engelmann, Trans. 
Acad. St. Louis. 8 :41.— Hemsley, Garden. 8 ; 133. 
Y. gloriosa tortulata Baker, Journ. Linn. Soc. Bot. 18 : 226. (1880). 
Y. falcata Garden. 16 : 369. (1879). 
Y. flexilis falcata Baker, Journ. Linn. Soc. Bot. 18: 224. (1880). 
Y. undulata Hort., in part. 
Differs from f. ensifolia chiefly in being shorter-stemmed and with 
the green leaves flatter and somewhat falcate, and from Y. gloriosa 
minor in its longer outer leaves being reflexed. 
Y. FLEXILIS SEMICYLINDRICA Baker, Journ. Linn. Soc. Bot. 
18 :224. (1880). 
Y. semicylindrica Baker, Gard. Chron. 1870; 1217. 
Differs from f. ensifolia inits firm and deeply concave narrower leaves 
(less than 20 mm. wide). 
Y. flexilis Boerhaavii (Baker) Trelease. 
Y. Boerhaavii Baker, Gard. Chron. 1870; 1217. Journ. Linn. Soc. Bot. 
18 ; 224. — Engelmann, Trans. Acad. St. Louis. $; 41. 
Chiefly differs from the preceding in its flat scarcely pungent leaves. 
