Comparative anatomy of Hawaiian Peperomia (Piperaceae) species
Date
1967
Contributor
Advisor
Department
Instructor
Depositor
Speaker
Researcher
Consultant
Interviewer
Narrator
Transcriber
Annotator
Journal Title
Journal ISSN
Volume Title
Publisher
University of Hawaii at Manoa
Volume
Number/Issue
Starting Page
Ending Page
Alternative Title
Abstract
In an effort to interpret the trends of specialization within the genus Peperomia, carpel morphology, meiotic chromosome number, meiotic irregularities, mode of leaf arrangement, and leaf and stem anatomy of 26 Hawaiian species of Peperomia have been .studied . Based on the available data, the following trends of specialization may have occurred in the genus: 1. There has been a reduction in the number of carpels composing the gynoecium. A tricarpellary gynoecium has given rise to a bicarpellary, and finally to a monocarpellary gynoecium. Such a trend is demonstrated by a reduction of the number of stigmas, as well as by a reduction in number of dorsal carpellary bundles in the ovary wall. 2. The basic chromosome number of the Hawaiian species of Peperomia is n =22, and one species has a variation of n =24. Polyploidy has been observed, and numbers of n = 44 and n = 48 have been recorded. The presence of meiotic irregularities and polyploidy suggest the possible roles of hybridization and polyploidy in speciation within the genus. The possible role of alteration of chromosome number in somatic cells in the speciation of the Hawaiian species is discussed. 3. Whorled leaf arrangement in the genus Peperomia has been derived from a spiral phyllotaxy. It is suggested that the whorled arrangement was brought about by three factors, Le., the failure of internodes to elongate, the lateral fusion of leaf primordia, and the fusion of the neighboring leaf traces. The failure of internodes to elongate is due to reduction of both cell division and cell elongation. 4. In this genus, vascular bundles are scattered in the pith resembling those of monocotyledons. Secondary growth has been greatly reduced through the elimination of cambial activity. The loss of cambial activity, and the reduction of the development of pericycle and endodermis, as well as the absence of xylem fibers are interpreted here as degrees of advancement toward simplification from the related genus Piper. The results obtained from studies of the number s of carpels and chromosomes do not support Yuncker's grouping of the species into subgenera.
Description
Keywords
Peperomia
Citation
Extent
Format
Geographic Location
Hawaii
Time Period
Related To
Theses for the degree of Doctor of Philosophy (University of Hawaii (Honolulu)). Botany; no. 137
Related To (URI)
Table of Contents
Rights
All UHM dissertations and theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission from the copyright owner.
Rights Holder
Local Contexts
Collections
Email libraryada-l@lists.hawaii.edu if you need this content in ADA-compliant format.