70 
A. B. Rcndle. 
ment. In the female the terminal bicarpellary pistil is at its first 
appearance flanked right and left by a small outgrowth, the 
bracteole rudiment. The degree of development of the bracteoles 
varies in the three genera (Gale, Comptoma and Myrica), and affords 
one of the best characters for generic diagnosis. They form, in 
brief, a cupular perianth-like structure which in Gale and Comptoma 
are agents for distributing the fruit. The association of these 
bracteoles with the sporophylls both in origin and position is so 
close that they might as well be regarded as a perianth. Presum¬ 
ably they are homologous structures in the two sexes, and there is 
no reason to suppose that the unisexual flowers are reduced from an 
hermaphrodite type, and therefore no reason to derive them from 
stamens. Their development suggests that they are foliar 
outgrowths below the sporophylls variously elaborated in the three 
genera and the flowers of the two sexes for protective and seed- 
distributing functions. 
In Juglandaceae the relationship between perianth and bracteole 
is very close. A rudimentary pistil is sometimes present in the 
male flower and it has been suggested that the general unisexual 
condition has arisen by reduction of hermaphrodite flowers. The 
male flower of Platycarya consists of 8-10 stamens in the axil of a 
bract, there is no trace of a perianth, but in the female flower the pair 
of bracteoles are united with the sides of the ovary suggesting an 
epigynous perianth. Similarly in Carya the male flower is naked, 
but in the female there is a single posterior perianth leaf which like 
the bract and the lateral pair of bracteoles is united with the ovary 
the four leaves simulating a 4-partite perianth. Engelhaydtia, 
Pterocarya and Juglans have a generally 4-partite perianth in flowers 
of both sexes. In the male the floral axis is elongated in the 
direction of the subtending bract along which bracteoles and 
perianth leaves are arranged below the stamens ; the perianth leaves 
bear a strong resemblance to the bracteoles with which they share 
the protection of the stamens, but are generally smaller. In the 
female flowers of Engelhardtia and Pterocarya the perianth is 
epigynous, while in Juglans the bracteoles are united with the ovary 
and form a toothed ring below the perianth. There is a strong 
suggestion of homology of perianth and bracteoles, and it is difficult 
to imagine a different origin for the two sets of leaves. It is of 
course possible, assumiug the derivation of the flowers from an 
hermaphrodite type, to regard perianth and bracteoles alike as 
barren sporophylls. 
