| Abstract Detail
Recent Topics Posters Tepe, Eric J. [1], Kelley, Walter A. [2], Rodriguez, Genoveva [3], Dyer, Lee A. [3]. Convergent morphology of ant-occupied stems in neotropical Piper (Piperaceae). The stems of some myrmecophytes in Piper are used as domatia by resident ant colonies. Hollow, ant-occupied stems were previously known only from southern Central America in four species of Piper sect. Macrostachys; however, here we present two additional, unrelated, hollow-stemmed myrmecophytes from Ecuador: P. immutatum (sect. Radula) and P. pterocladum (sect. Schilleria). Although similar superficially, the stem cavities in each of these sections of Piper differ in both morphology and development. The stem cavities of P. immutatum are formed during stem development. They are lysigenous in origin and begin forming only a few millimeters behind the apical meristem. This mode of cavity formation differs markedly from myrmecophytes in sect. Macrostachys in which the stems remain solid unless excavated by the specialized ant partner Pheidole bicornis. In P. immutatum, ants clear away remnants of dead cells, but do not further enlarge the diameter of the cavity and, unlike the stems in sect. Macrostachys, do not produce wound-response tissue around the cavity. The entrance holes through the stems of P. immutatum are formed through apoptotic processes and are located at each node below the point of petiole insertion, whereas those in sect. Macrostachys are excavated by the ants through the branch gap in the leaf axil. The stem cavities of P. pterocladum are similar to those of sect. Macrostachys in that they remain solid until they are excavated by ant residents, and once excavated, are lined with wound-response tissue. This study emphasizes the need for close examination and careful comparison of apparently homologous, ant-associated structures in specialized myrmecophytes.
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1 - Miami University, Department of Botany, 316 Pearson Hall, Oxford, OH, 45056, USA
2 - Mesa State College, Department of Biology, 1100 North Avenue, Grand Junction, CO, 81501, USA
3 - Tulane University, Department of Ecology & Evolutionary Biology, 310 Dinwiddie Hall, New Orleans, LA, 70118, USA
Keywords:
myrmecophytes
cauline domatia
Piper
Piperaceae
plant-insect interaction
comparative morphology.
Presentation Type: Recent Topics Poster
Session: P
Location: Exhibit Hall (Northeast, Southwest & Southeast)/Hilton
Date: Sunday, July 8th, 2007
Time: 8:00 AM
Number: P79010
Abstract ID:2554 |
