44 MISSOURI BOTANICAL GARDEN. 
ico, and, after a break of unknown extent, into the center 
of Central America, and eastwards to the Atlantic coast and 
the Bermudas and eastern Antilles. The capsular species 
are the prevalent northern form, and reach from South 
Dakota to the Mexican state of Durango, and from the 
Atlantic coast to Nevada, with the exception of the Great 
Lake region and the upper Mississippi river and its tribu- 
taries from the east. The baccate species with papery core 
are of the southern Rocky Mountain and western region, 
reaching the Pacific coast in the southern part of California 
and at the extremity of Lower California, and are the preva- 
lent form of the high table land of Mexico. A single spe- 
cies with coreless fleshy fruit appears to be restricted to the 
southern Atlantic coast of the United States, a small part 
of the Gulf coast, and some of the islands to the east, 
though it has given rise to a marked variety in the isolated 
peninsula of Yucatan; and a single species with the foliage 
of this outlying species but forming a core in the fruit 
occurs in Central America, where, though abundantly culti- 
vated, its distribution is unknown. Several species and 
many varieties are known only in gardens, and two species 
with very aberrant fruit are of local distribution on the 
southeastern seacoast of the United States. — Plate 99. 
KEY TO SPECIES. 
Fruit erect, capsular, dehiscent. Seeds thin, flat, margined: albumen 
not ruminated. § CHAENOYUCCA. 
Leaves finely filiferous (entire in forms of the second). 
Style oblong, white. 
Inflorescence a long-peduncled panicle (subracemose in 
some garden forms of Y. flaccida). 
Leaves lanceolate or spatulate, often plicate, at most 
very narrowly lined with gray or brown next the mar- 
ginal threads. 
Leaves rigid for the group, rather coarsely curly- 
filiferous, subspatulate. Segments of young fruit 
regularly convex. Y. filamentosa. 
Leaves more flexible and attenuate, with finer 
straighter threads. Segments of young fruit 
with angular facets. Y. flaccida. 
