LORRHY A 
June, 1012 
Vol. 12 ; No. 6 
INDUCED HERMAPHRODISM IN ACER NEGUNDO L. 
Bv CHARLES GORDON FRASER 
In the sixth edition of Gray's Manual the ash-leaved maple 
or box elder is classified as Negundo Aceroides Moench., in a 
separate genus following the genus Acer. The first and one of 
the chief distinctions made is that the genus Acer is polygamo- 
dioecious, whereas Negundo is dioecious. Sargent (1905) makes 
the same distinction, describing Negundo as: '"Staminate and 
pistillate on separate trees, . . . (stamens) none in the pistillate 
flower." In the seventh—and latest—edition of Gray's Manual 
this species is given the classification Acer Negundo L., but is 
placed in a second sub-division of the genus which is characterized 
as "strictly dioecious.” Britton (1908) classifies this form as 
Acer Negundo L., with the synonym Negundo Aceroides Moench., 
and description: “Staminate and pistillate flowers on different 
trees," 
On May 15, 1909, the writer came across an exception to the 
strict dioeciousness of А. Negundo. By the banks of a creek 
near Weston, Ontario, in a grove of this species, a tree was found 
on one limb of which hermaphrodite flowers were borne in con- 
siderable numbers. For at least four years previous, as could 
readily be determined by the winter bud scars, and the per- 
sistent pedicels, the tree had fruited copiously, this particular 
limb not excepted. On the main part of the tree, which was 
searched carefully, only normal pistillate flowers were found. 
By some accident the limb in question had been partly split 
from the trunk, in such a way as to leave about one fifth of its 
bark and cambium intact. Fig. І shows the general appearance 
of the tree with the partly detached branch; fig. 2 indicates the 
[No. 5, Vol. 12, of TORREYA, comprising pp. 97-120, was issued 10 May 1912.] 
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