KIRCHOFF, BRUCE*, SONJA CAUBLE, ELIZABETH SHELTON, AND ALLYSON PREVETTE. Department of Biology, P.O. Box 26174, University of North Carolina at Greensboro, Greensboro, NC 27402-6174. - The Structure of the Banana Inflorescence.
The morphology of the banana inflorescence has been described as a
long terminal raceme, a terminal panicle, and a serial flower
assemblage. Mclean Thompson proposed that the banana inflorescence was
an aerial stem with spirally arranged leaves in the axils of which
grow cones of flowers. The observations of Abraham Fahn contest this
hypothesis and favor another hypothesis also proposed by Thompson in
which the flower-groups are cincinni. Our research has examined
inflorescence development in Musa velutina. Musa is
monecious, containing unisexual flowers arranged in hands. The number
of flowers per hand varies. Each hand develops in the axil of a
primary bract and consists of two rows of flowers. The entire
inflorescence is made up of a definite number of female hands, a small
number of transitional hands, and an indefinite number of male hands.
Based on his observations of Musa acuminata and Musa
balbisiana, Fahn suggests that the sequence of flower initiation
begins with the primordium farthest right in the adaxial row. This is
followed by the development of the primordium directly adjacent to
the first. The third is the right most primordium in the abaxial row.
He suggests the sequence continues to alternate, adaxial to abaxial,
throughout the hand. Our research does not wholly agree with these
findings. Many of the hands we studied demonstrate the sequence of
flower initiation beginning from the center of the hand and
progressing outward. In many instances the right-most flower appears
to be younger than the flower adjacent to it. While we have observed
the adaxial-abaxial arrangement of flowers we have not observed
development of flower primordia following an alternating sequence
between the rows.
Key words: banana, development, inflorescence, morphology, Musa