Among the monandrous orchids, usually three bundles 
from the inflorescence axis deviate into the floral axis and 
while doing so break up into the six main traces of the 
ovary. The exact method of their breaking up varies 
among the different genera. Further, the different levels 
at which they break up is also variable to some extent 
within the same species. In Habenaria (Fig. 2 B), two 
of the three bundles that deviate from the inflorescence 
Fig. 2. A to E, Diagrams illustrating methods of the differentiation 
of the six main traces of the ovary from the vascular bundles of the 
inflorescence axis. 
axis directly constitute those main traces of the ovary 
underlying the lateral petals (LP); the third bundle not 
only gives rise to the midrib trace of the bract (Br), but 
also, by further breaking up, constitutes the remaining 
four main traces of the ovary, underlying the dorsal sepal 
(DS), the two lateral sepals (LS) and the median petal 
(MP). In Vanilla, some species of Dendrobium, Rhyn- 
chostylis and a few others (Fig. 2 C), each of the three 
vascular bundles of the inflorescence axis that enters the 
flowers gives rise to two main traces of the ovary, the 
traces occupying positions under the adjacent perianth 
members (LLP, DS; LP, LS; MP, LS); the median 
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