1923] Brackett,—American Species of Hypoxis 121 
in his subgenus Euhypoxis, characterized by versatile anthers, while 
the species with basifixed anthers (and glabrous foliage) constituted 
his subgenus Zanthe of Australia and the Cape of Good Hope. H. 
sessilis of the Atlantic coastal plain is, therefore, of special interest 
since it has the pilose leaves and perianth of Euhypoxis but the 
basifixed anthers of Zanthe. 
Baker's reduction of all the species in North and South America 
to three was natural because he was working with only the super- 
ficial characters. In attempting to place satisfactorily material of 
H. sessilis (the American species with basifixed anthers, not generally 
recognized since its publication by Linnaeus), it was found that the 
specles of the United States are clearly separated by their seeds. 
The seed-characters proved so satisfactory, in this limited area, that 
the study was extended to cover the plants of the West Indies, Mexico, 
Central and South America. In carrying on this work I have ex- 
amined the material in the Gray Herbarium and have been gener- 
ously loaned the American specimens in the herbaria of the New 
York Botanical Garden, the Academy of Sciences of Philadelphia, 
the United States National Museum and the Missouri Botanical 
Garden. I wish here to express my thanks for the use of this material 
to those in charge of the different collections: Professors Robinson 
and Britton and Doctors Pennell, Maxon and Greenman. Through- 
out the work I have had the constant suggestions and aid of Pro- 
fessor Fernald and much aid in the bibliography from Miss Day and 
Miss Vincent of the Gray Herbarium library. 
I have made critical studies of all the fruiting material available. 
The seed-characters of the plants from south of the United States 
prove as satisfactory as was hoped and, supported by other characters, 
indicate that there are at least fifteen, instead of only three American 
species. The regions in America where Hypoxis seems to have the 
greatest variety of species are the southeastern and Gulf coastal 
plain of the United States (from South Carolina to Texas), the upland 
of Mexico and the northern Andes. It is probable that South America 
will furnish more species than are here treated: the material seen 
from that region has been very scanty and at least two of the South 
American species described by Humboldt, Bonpland and Kunth have 
not been satisfactorily matched, and new species are likely to be dis- 
covered. 
