10. Melochia L.
(Goldberg, 1967)
About 60
species, nearly worldwide, most diverse in the New World tropics.
Traditionally, Melochia
has been treated in the segregate family Sterculiaceae, a mostly tropical group
of some 65 genera and more than 1000 species, these mostly shrubs or trees.
However, molecular studies have shown that the genera group into two main
lineages, one of which appears more closely related to one of the two major
groups of former Tiliaceae and the other of which is only distantly related
within the Malvaceae in the broad sense and closer to the other portion of the
former Tiliaceae (Whitlock et al., 2001).
It should be
noted that the flowers of some species of Melochia do not possess an
epicalyx of closely subtending bracts and such species cannot be correctly
identified to genus in the key above. Also, members of Melochia tend to
produce long-styled and short-styled flowers (heterostyly). The staminal tube
can be relatively short in long-styled flowers.