OWEN, JR., T. PAGE* AND KRISTEN A. LENNON1. Department of Botany, Connecticut College, New London, CT 06320, 1Current address: Department of Botany and Plant Sciences, University of California, Riverside, California, 92521. - Structure and development of the pitchers from the carnivorous plant Nepenthes alata.
The pitchers of the tropical carnivorous plant Nepenthes alata
are highly specialized organs for the attraction, capture and
absorption of insect-derived nutrients. We examined the structure and
development of these pitchers, with particular focus on the nectaries
and digestive glands. Immature pitchers develop at the tips of
tendrils and have a lid structure that tightly seals the pitcher
opening. Lid opening correlates with the end of pitcher elongation.
Opened pitchers have a ridged peristome containing a row of individual
large nectaries. Like other members of the genus, the upper one-third
of the pitcher is covered by a thick coating of epicuticular waxy
scales. Scattered within this zone are cells with a protruding ridge
that, together the wax, may help retain insect prey by limiting
available footholds. Cross-sections show the ridge is formed by
asymmetric divisions of the epidermal cells. The basal region of the
pitcher has large multicellular glands that develop from single
epidermal cells. These glands are closely associated with underlying
vascular traces and provide a mechanism for supplying fluid to closed
immature pitchers. A suberized layer at the gland base may restrict
solute flow into the pitcher fluid. The SEM was funded in part by an
NSF Instrument and Laboratory Improvement Grant (DUE-9552109).
Key words: carnivory, gland development, nectary, Nepenthaceae, Nepenthes alata, pitcher plant