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

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Published: 2012-12-12
Keywords:
arid regions, diaspores, dispersal, myxospermy, Namaqualand, scanning electron microscopy, Succulent Karoo

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M.W. van Rooyen
H.F. Makouate
C.F. van der Merwe

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.

Article Details

Issue

Vol. 42 No. 1 (2012): Bothalia

Section

Original research, Reviews, Strategies, Case studies
Creative Commons License

This work is licensed under a Creative Commons Attribution 4.0 International License.

How to Cite

van Rooyen, M., Makouate, H. and van der Merwe, C. (2012) “Anatomy of myxospermic diaspores of selected species in the Succulent Karoo, Namaqualand, South Africa”, African Biodiversity & Conservation, 42(1). Available at: https://mail.abcjournal.org/index.php/abc/article/view/255 (Accessed: 2 May 2026).

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