Original Research

Anatomy of myxospermic diaspores of selected species in the Succulent Karoo, Namaqualand, South Africa

H. F. Makouate, M. W. van Rooyen, C. F. van der Merwe
Bothalia | Vol 42, No 1 | a4 | DOI: https://doi.org/10.4102/abc.v42i1.4 | © 2012 H. F. Makouate, M. W. van Rooyen, C. F. van der Merwe | This work is licensed under CC Attribution 4.0
Submitted: 09 December 2012 | Published: 12 December 2012

About the author(s)

H. F. Makouate, Department of Plant Science, University of Pretoria, South Africa
M. W. van Rooyen, Department of Plant Science, University of Pretoria, South Africa
C. F. van der Merwe, Laboratory for Microscopy and Microanalysis, University of Pretoria, South Africa

Full Text:

PDF (701KB)

See Updates


Share this article

Bookmark and Share

Abstract

Environmental conditions encountered in arid ecosystems differ vastly from those in more mesic ecosystems. Dispersal strategies in arid environments reflect these differences and many mechanisms have evolved that restrict or hinder dispersal. Myxospermy is a trait developed by plant species from arid regions to restrict diaspore dispersal by means of an anchorage mechanism. Several of the abundant plant species in Namaqualand, within the arid Succulent Karoo Biome, display myxospermy. Diaspores of these species produce copious amounts of mucilage when they are moistened and are anchored to the soil once the mucilage dries out again. This study investigated the origin of the mucilaginous layer of 12 species anatomically, using both light and scanning electron microscopy. The mucilage production of the species investigated could best be grouped into three types: 1, epidermal and sub-epidermal cells of seeds and achenes; 2, specialized tissue in wings or the pappus of achenes; and 3, mucilage excreting hairs. Previous systems for classifying the different types of mucilage production did not recognize the mucilaginous nature of wings or a pappus. A short note on the composition of the mucilage is included.

Keywords

Arid Regions; Diaspores; Dispersal; Myxospermy; Namaqualand; Scanning Electron Microscopy; Succulent Karoo

Metrics

Total abstract views: 1795
Total article views: 2181

 

Crossref Citations

1. The micro- and nanoscale spatial architecture of the seed mucilage—Comparative study of selected plant species
Agnieszka Kreitschitz, Stanislav N. Gorb, David A. Lightfoot
PLOS ONE  vol: 13  issue: 7  first page: e0200522  year: 2018  
doi: 10.1371/journal.pone.0200522