86 MISSOURI BOTANICAL GARDEN. 
bore fruit,* once when Dr. Mellichamp found fruit on a 
plant which had bloomed simultaneously with Y. silamen- 
tosa,t and a third instance observed by me on Tybee Island 
in May last, (Plate 44, f. 2) on a plant which must have 
bloomed just about as Y. filamentosa was coming into 
flower. The species, therefore, is all but restricted for its 
propagation to vegetative methods, by which its present dis- 
tribution along the sand dunes can fairly well be explained, 
since the well-budded thick subterranean shoots possess 
great vitality. 
What has been said of the ecology of Y. gloriosa might 
be repeated almost verbatim for Y. recurvifolia, which is 
likewise autumnal-flowering, and the fruit of which, — 
barring several rather questionable statements in gardening 
journals, —to my knowledge has never been observed until 
Dr. Mellichamp, in the summer of 1901, found plants fruit- 
ing in cultivation in the neighborhood of Charleston, and 
furnished the material from which the description and 
illustration here published were drawn. The occurrence 
of Y. recurvifolia on several islands between the delta of 
the Mississippi and the mouth of the Mobile river, which is 
not connected with the present question, may, perhaps, 
have been brought about by currents transporting rhizome 
fragments derived from plants cultivated somewhere along 
one of the rivers opening on the northern shore of the 
Gulf. 
These ecological considerations suggest with force that 
if species in the time-honored use of that term, Y. gloriosa 
and Y. recurvifolia, so far as their spontaneous forms are 
concerned, are of unexpectedly restricted distribution in a 
region where their congeners are widespread, and that they 
manifest a surprising disharmony with their surroundings 
which, because of the rigid pollination requirements of all 
of this genus but alozfolia, has thrown them into almost 
* Engelmann, Trans. Acad. Sci. St. Louis. $211. 
+ Rept. Mo. Bot. Gard. 43199. 
