Hostname: page-component-cd9895bd7-gxg78 Total loading time: 0 Render date: 2024-12-27T22:32:47.107Z Has data issue: false hasContentIssue false

SYSTEMATIC AND ECOLOGICAL SIGNIFICANCE OF SEED COAT MORPHOLOGY IN SOUTH AFRICAN CAMPANULACEAE SENSU STRICTO

Published online by Cambridge University Press:  18 October 2011

C. N. Cupido
Affiliation:
South African National Biodiversity Institute, Compton Herbarium, Private Bag X7, Claremont 7735, South Africa. E-mail: c.cupido@sanbi.org.za
W. M. M. Eddie
Affiliation:
Office of Lifelong Learning, University of Edinburgh, 11 Buccleuch Place, Edinburgh EH8 9LW, Scotland, UK. E-mail: weddie1@staffmail.ed.ac.uk
L. R. Tiedt
Affiliation:
Laboratory for Electron Microscopy, University of the North West, Private Bag X6001, Potchefstroom 2520, South Africa. E-mail: louwrens.tiedt@nwu.ac.za
Get access

Abstract

The seed coat morphology of 50 species of Campanulaceae sensu stricto, representing all 10 South African genera, was studied by scanning electron microscopy to gauge its usefulness in the diagnosis of genera or to support clades. Possible correlations with life form (annual, herbaceous and woody perennial) and ecological requirements such as fire response, rainfall requirements, bedrock and soil preferences, as well as habitat (e.g. fynbos, strandveld, renosterveld, grassland and karoo), were also investigated. Patterns of variation are described and interpreted as conforming to two seed coat types: reticulate (Type 1) and striate/wavy (Type 2). Type 1 seeds are further divided into eight subtypes. Some general trends emerged; for example, Type 1 seeds occur in all major clades of wahlenbergioids, Type 1A with a smooth coarsely reticulate surface being predominant in fynbos taxa, all of which are woody perennials. Several of the Type 1 seeds, together with Type 2 seeds, also occur in species with wider ecological amplitude, for example in karoo, strandveld or montane grasslands. In Siphocodon there is remarkable disparity in seed type between species. These variations in seed type generally appear to accord with current knowledge of climatic changes and soil evolution during the Tertiary of South Africa, and may be useful indicators of generic emergence and mosaic speciation in the major lineages of wahlenbergioids. However, it was concluded that seed coat types do not correlate closely enough with specific ecological requirements or life forms to be of unequivocal predictive value. Also, apart from Merciera and Treichelia, they are of limited use as a diagnostic character for genera, but are useful for distinguishing species.

Type
Articles
Copyright
Copyright © Trustees of the Royal Botanic Garden Edinburgh 2011

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Akcin, T. A. (2009). Seed coat morphology of some Turkish Campanula (Campanulaceae) species and its systematic implications. Biologia 64: 10891094.Google Scholar
Alçitepe, E. (2010). Studies on seed morphology of Campanula L. section Quinqueloculares (Boiss.) Phitos (Campanulaceae) in Turkey. Pakistan J. Bot. 42: 10751082.Google Scholar
Barthlott, W. (1981). Epidermal and seed surface characters of plants: systematic applicability and some evolutionary aspects. Nordic J. Bot. 1: 345355.Google Scholar
Barthlott, W. (1984). Microstructural features of seed surfaces. In: Heywood, V. H. & Moore, D. M. (eds) Current Concepts in Plant Taxonomy, pp. 95105. London: Academic Press.Google Scholar
Behnke, H.-D. & Barthlott, W. (1983). New evidence from the ultrastructural and micromorphological fields in angiosperm classification. Nordic J. Bot. 3: 4366.Google Scholar
Carbutt, C. & Edwards, T. (2001). Cape elements on high-altitude corridors and edaphic islands: historical aspects and preliminary phytogeography. Syst. Geogr. Pl. 71: 10331061.Google Scholar
Corner, E. J. H. (1976). The Seeds of Dicotyledons. 2 vols. Cambridge: Cambridge University Press.Google Scholar
Cupido, C. N. (2009). Systematic studies of the South African Campanulaceae sensu stricto with an emphasis on generic delimitation. PhD Thesis, University of Cape Town, Cape Town.Google Scholar
Eddie, W. M. M. (1984). A systematic study of the genus Musschia Dumortier with reference to character diversity and evolution in the Campanulaceae: Campanuloideae. MSc thesis, University of Reading, London.Google Scholar
Eddie, W. M. M. (1997). A global reassessment of the generic relationships in the bellflower family (Campanulaceae). PhD thesis, University of Edinburgh, Edinburgh.Google Scholar
Eddie, W. M. M., Shulkina, T., Gaskin, J., Haberle, R. C. & Jansen, R. K. (2003). Phylogeny of Campanulaceae s.str. inferred from ITS sequences of nuclear ribosomal DNA. Ann. Missouri Bot. Gard. 90: 554575.CrossRefGoogle Scholar
Eddie, W. M. M., Cupido, C. N. & Skvarla, J. J. (2010). Pollen and reproductive morphology of Rhigiophyllum and Siphocodon (Campanulaceae): two unique genera of the fynbos vegetation of South Africa. Bothalia 40: 103115.Google Scholar
Geslot, A. (1980). Le tegument seminal de quelques Campanulacees: etude au microscope electronique and balayge. Adansonia 19: 307318.Google Scholar
Givnish, T. J., Sytsma, K. J., Smith, J. F. & Hahn, W. J. (1995). Molecular evolution, adaptive radiation, and geographic speciation in Cyanea (Campanulaceae, Lobelioideae). In: Wagner, W. L. & Funk, V. A. (eds) Hawaiian Biogeography: Evolution in a Hot-spot Archipelago, pp. 288337. Washington, DC: Smithsonian Institution Press.Google Scholar
Goldblatt, P. (1978). An analysis of the flora of southern Africa: its characteristics, relationship and origins. Ann. Missouri Bot. Gard. 65: 369436.Google Scholar
Haberle, R. C., Dang, A., Lee, T., Peňaflor, C., Cortes-Burns, H., Oestreich, A. et al. . (2009). Taxonomic and biogeographic implications of a phylogenetic analysis of the Campanulaceae based on three chloroplast genes. Taxon 58: 715734.Google Scholar
Haridasan, V. K. & Mukherjee, P. K. (1988). Seed surface features of some members of the Indian Campanulaceae. Phytomorphology 37: 277285.Google Scholar
Hong, D.-Y. & Pan, K-Y. (1998). The restoration of the genus Cyclocodon (Campanulaceae) and its evidence from pollen and seed coat. Acta Phytotax. Sin. 36: 106110.Google Scholar
Linder, H. P. (1990). On the relationship between the vegetation and floras of the Afromontane and the Cape regions of Africa. Mitt. Inst. Allg. Bot. Hamburg 23b: 777790.Google Scholar
Linder, H. P. (2003). The radiation of the Cape flora, southern Africa. Biol. Rev. 78: 597638.Google Scholar
Mucina, L. & Rutherford, M. C. (2006). The vegetation of South Africa, Lesotho and Swaziland. Strelitzia 19: 53219. Pretoria: South African National Biodiversity Institute.Google Scholar
Murata, J. (1992). Systematic implications of seed coat morphology in Lobelia (Campanulaceae–Lobelioideae). J. Fac. Sci. Univ. Tokyo, Sect. 3, Bot. 15: 155172.Google Scholar
Netolitzky, F. (1926). Anatomie der Angiospermen-Samen. Campanulaceae. In: Linsbauer, K. (ed.) K. Linsbauer’s Handbuch der Pflanzenanatomie 10: 7173.Google Scholar
Shetler, S. G. & Morin, N. R. (1986). Seed morphology in North American Campanulaceae. Ann. Missouri Bot. Gard. 73: 635688.Google Scholar
Takhtajan, A. (1991). Evolutionary Trends in Flowering Plants. New York: Columbia University Press.Google Scholar
Thulin, M. (1974). Gunillaea and Namacodon. Two new genera of Campanulaceae in Africa. Bot. Not. 127: 165182.Google Scholar
Thulin, M. (1975). The genus Wahlenbergia s.l. (Campanulaceae) in Tropical Africa and Madagascar. Symb. Bot. Upsal. 21: 1223.Google Scholar
Welman, W. G. & Cupido, C. N. (2003). Campanulaceae. In: Germishuizen, G. & Meyer, N. L. (eds) Plants of southern Africa: an annotated checklist. Strelitzia 14: 336346. Pretoria: National Botanical Institute.Google Scholar