Desmopsis, a new genus of Annonaceae 
WILLIAM EDWIN SAFFORD 
(WITH PLATES 7-9 AND ONE TEXT FIGURE) 
The genus Unona was based by the younger Linnaeus on an 
American plant, the peyrico-boom of Surinam, belonging to the 
previously established genus Xylopia. Its type, Unona discreta 
L. f., is identical with either Xylopia frutescens Aubl. or X. sal- 
cifolia Dunal, and is certainly not congeneric with the Asiatic 
plants usually referred to the genus Unona. Recognizing that 
Unona must become a synonym of Xylopia and that the name 
could no longer be used for any other genus, the writer restored the 
generic name Desmos, established by Loureiro in 1790, for the 
Asiatic Unona discolor, believed by Vahl (1791) to be a congener 
of the American U. discreta but which proved to be identical with 
Loureiro’s Desmos chinensis. The type of Loureiro’s genus, 
Desmos cochinchinensis, was arbitrarily renamed by Dunal (1817) 
Unona Desmos. The necessity of restoring the generic name 
Desmos* in accordance with accepted rules of nomenclature was 
recognized by Mr. Elmer D. Merrill, in his “Studies on Philip- 
pine Annonaceae.’’t 
That there are no American species congeneric with Desmos 
(Unona Vahl) was recognized by the writer, who in the publication 
above cited referred Unona panamensis Robinson and U. bibrac- 
teata Robinson to Unonopsis, established by Robert E. Fries in 
1900. A further study of the genus Unonopsis, however, showed 
that Fries included in it plants differing widely in inflorescence 
and in the number and arrangement of the ovules. In proposing 
* “‘ Desmos the proper generic name for the so-called Unonas of the Old World. 
Bull. Torrey Club 39: 501-508. 1912. 
vely shown that the genus Unona Linn. f. was 
properly be considered under this generic designation, and 
taken up. the generic appelation Desmos for the oriental forms, 
proposed by Loureiro in 1790.” Phil. Jour. Sci. Bot. 10: 234-1915. 
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