LITT, AMY* AND DENNIS W. STEVENSON. New York Botanical Garden, Bronx, NY 10458. - Floral morphology of the Vochysiaceae: asymmetry and pseudomonomery.
Flowers of Vochysiaceae are distinguished by having a single fertile
stamen, a spurred calyx, and generally fewer than five petals. The
family has traditionally been divided into two tribes, but molecular
phylogenetic analysis shows three groups, represented by the genera
Vochysia, Qualea, and Erisma. Examination of
floral morphology supports this three-part division. The flowers of
the Vochysia and Erisma groups are bilaterally
symmetrical, with the stamen directly in front of a petal. Those of
the Qualea group are asymmetrical, with the stamen slightly
offset. The Vochysia and Qualea groups have a
trilocular, superior ovary surrounded by a floral cup, while the
Erisma group has a unilocular inferior ovary (described as
pseudomonomerous). Morphological, developmental, and anatomical
studies were undertaken to determine the nature of the Erisma
gynoecium and the position of the Qualea stamen. Patterns of
vasculature support the notion that the position of the stamen in
Qualea is fundamentally different from that in the other
genera, and that it is not directly in front of either a sepal or the
petal. SEM and anatomical studies in Erisma failed to produce
any substantive evidence that the ovary is pseudomonomerous. Its
development and vasculature are distinctly different from that of the
other groups.
Key words: pseudomonomery, symmetry, Vochysiaceae