Phone: 021 650 4037 
Room No.: 4.24 (HW Pearson Building)




Research Interests

My research focuses on understanding evolution as a process, the influence of biotic and abiotic forces on the outcomes of this process, and how together these create and structure biological diversity across a range of phylogenetic, spatial, and temporal scales. Since selection on life histories may be a key driver of differentiation, testing evolutionary predictions from life history theory is an area of particular interest. Phylogeny reconstruction is central to my research programme, and I employ the full spectrum of molecular markers and associated analytical techniques in my research.

Although I have worked on most of the major groups of green plants, the bryophytes, especially mosses, are my favourite organisms. In many parts of the world this ecologically and evolutionarily important group is still very poorly known. Here in the western Cape of South Africa, for example, I estimate that 30-50% of the bryophyte flora is still undescribed. The basic taxonomic endeavour of species discovery and description, based on personal and herbarium collections, thus constitutes a significant part of my research. Discoveries made in the course of this fundamental undertaking often form the basis for more detailed research in evolution and ecology – for example understanding the many, apparently quite recent, disjunctions between the Cape and Australia.

Key Research Categories
Adaptive Evolution: Biodiversity: Biometrics and Multivariate Statistics in Evolutionary Biology: Bryophyte Taxonomy and Systematics: Evolutionary Biology: Life History Evolution: Life History Theory: Molecular Systematics: Neutral Evolution: Phylogenetic Diversity: Phylogeny Reconstruction: Phylogeography: Population Differentiation: Population Ecology: Population Genetic Structure: Speciation


Educational History:

  • 1989-1992. Ph.D. University of Reading, England. Life History Evolution in Mosses: Constraints, Tradeoffs and Local Adaptation; Supervised by Dr. R.E. Longton.
  • 1984-1987. M.Sc. Memorial University of Newfoundland. The influence of habitat availability, dispersal factors and plant-microhabitat relationships on the structure of the moss flora of Terra Nova National Park, Newfoundland; Supervised by Dr. G.R. Brassard.
  • 1978-1984. B.Sc.(Hons.), Memorial University of Newfoundland. Ecology and phytogeography of mosses with northern distributions in Newfoundland; Supervised by Dr. G.R. Brassard.


  • 1989-1992. Rothermere Fellowship. (Rothermere Fellowships Trust, University College, London).
  • 1990-1992. Overseas Research Fellowship (British).

Employment History:

  • January 2006 - Present. Full Professor, Department of Botany, University of Cape Town.
  • January 2003- December 2005. Associate Professor, Department of Botany, University of Cape Town.
  • January 2000 - December 2002. Lecturer, Department of Botany, University of Cape Town.
  • June 1994-1999. Advanced Research Fellow. Natural Environmental Research Council, University of Reading.
  • Jan. 1993- June 1994. Postdoctoral Researcher, Louisiana State University. Phylogenetic studies on bryophytes and algae using rRNA sequences.
  • May-Sept., 1988. Group Botanist. British Ministry of Defence. Joint Services Expedition to Borup Fiord, Ellesmere Island. Ecological and phytogeographical studies of the vascular and bryophyte floras.
  • 1987-1989. Laboratory Instructor, Memorial University of Newfoundland.

Professional Affiliations/Duties:

Associate Editor Molecular Phylogenetics and Evolution
Associate Editor Lindbergia

Fellow of the Linnean Society (London), Member of The American Bryological and Lichenological Society, The American Society for Plant Taxonomy, The International Association of Bryologists, The International Association of Plant Taxonomists, South African Society for Systematic Biology.

Past Secretary of the South African Society for Systematic Biology.
Past Council Member of The British Bryological Society
Past Council Member of The International Association of Bryologists


  1. Ah-Peng, C., Bardat, J., Stamenoff, P., Hedderson, T.A. & Strasberg, D. 2010. Bryophytes de l'île de La Réunion : diversité, endémicité et conservation. Cryptogamie Bryologie. In Press
  2. Soderstrom, L, De Roo, R & Hedderson, T. 2010. Taxonomic novelties resulting from recent reclassification of the Lophoziaceae/Scapaniaceae clade. Phytotaxa 03: 47-53.
  3. Zander, R.H. & T.A. Hedderson 2009. Acaulonopsis, a new moss genus of the Pottiaceae from the Western Cape Province of South Africa, and comments on Vrolijkheidia. Journal of Bryology 31: 234-239.
  4. CBOL Plant Working Group (including T.A. Hedderson). 2009. A DNA barcode for land plants. Proceedings of the National Academy of Sciences 106: 12794-12797.
  5. Wilson, D., Stock W. & Hedderson T.A. 2009. Historical nitrogen content of bryophyte tissue as an indicator of increased nitrogen deposition in the Cape Metropolitan Area, South Africa. Environmental Pollution 157: 938-945.
  6. Hedderson, T.A. & R.H. Zander. 2008. Algaria nataliei (Pottiaceae), a new moss genus and species from the Western Cape Province of South Africa. Journal of Bryology 30: 192-195.
  7. Hedderson, T.A. & R.H. Zander. 2008. Vrolijkheidia circumscissa (Pottiaceae), a new moss genus and species from the succulent karoo of South Africa. Journal of Bryology 30: 143-146.
  8. Hedderson, T.A. & R.E. Longton. 2008. Local adaptation in moss life histories: population-level variation and a reciprocal transplant experiment. Journal of Bryology 30: 1-11.
  9. Hedderson, T.A. & R.H. Zander. 2008. Chenia ruigtevleia (Pottiaceae), a new moss species from the Western Cape Province of South Africa. The Bryologist 111: 496-500.
  10. Hedderson, T.A. & R.H. Zander. 2007. Ludorugbya springbokorum (Pottiaceae), a new moss genus and species from the Western Cape Province of South Africa. Journal of Bryology 29: 222-227.
  11. Klak, C., P.V. Bruyns & T.A.J. Hedderson. 2007. A phylogeny and new classification for Mesembryanthemoideae (Aizoaceae). Taxon 56: 737-756.
  12. Forest, F., R. Grenyer, M. Rouget, T.J. Davies, R.M. Cowling, D.P. Faith, A. Balmford, J.C. Manning, S. Proches, M. van der Bank, G. Reeves, T.A. Hedderson & V. Savolainen. 2007. Preserving the evolutionary potential of floras in biodiversity hotspots. Nature 445: 757-760.
  13. Hylander, K. & T.A. Hedderson. 2007. Does the width of isolated ravine forests influence moss and liverwort diversity and composition? - a study of subtropical forests in South Africa. Biodiversity and Conservation 16: 1441-1458.
  14. Hedderson, T.A. & R. Zander. 2007. A new South African species of Triquetrella with a phylogenetic and biogeographic hypothesis for the genus. Journal of Bryology 29: 151-160.
  15. Chase, M.W., R.S. Cowan, P.M. Hollingsworth, C. van den Berg, S. Madrinan, G. Petersen, O. Seberg, T. Jorgensen, K.M. Cameron, M. Carine, N. Pedersen, T.A.J. Hedderson, F. Conrad, G.A. Salazar, J.E. Richardson, M.L. Hollingsworth, T.G. Barraclough, L. Kelly & M. Wilkinson. 2007. A proposal for a standardised protocol to barcode all land plants. Taxon 56: 295-299.
  16. Bergh, N.G., T.A. Hedderson, H.P. Linder & W.J. Bond 2007. Paleoclimate-induced range shifts may explain current patterns of spatial genetic variation in renosterbos (Elytropappus rhinocerotis, Asteraceae). Taxon 56: 393-408.
  17. De Roo, R. T.A. Hedderson & L. Soderstrom. 2007. Molecular insights into the phylogeny of the leafy liverwort family Lophoziaceae Cavers. Taxon 56: 301-314.
  18. Crowe, T.M., R.C.K Bowie, P. Bloomer, T.G. Mandiwana, T.A. Hedderson, E. Randi, S.L Pereira, & J. Wakeling. 2006. Phylogenetics, biogeography and classification of, and character evolution in, gamebirds (Aves: Galliformes): effects of character exclusion, data partitioning and missing data. Cladistics 22: 1-38.
  19. Hedderson T.A. and J. Enroth. 2006. New national and regional bryophyte records: Neckera complanata. Journal of Bryology 28: 271-275.
  20. Conrad, F., G. Reeves, D. Snijman & T.A. Hedderson. 2006. Generic relationships within the tribe Haemantheae (Amaryllidaceae), based on plastid DNA sequence data. Pp 73-83. In: S.A. Ghazanfar & H.J. Beentje (eds.) Taxonomy and Ecology of African Plants, their Conservation and Sustainable Utilisation. Royal Botanic Garden, Kew.
  21. Hedderson, T.A. & T.L. Nowell. 2006. Phylogeography of Homalothecium sericeum: toward a reconstruction of glacial survival and postglacial migration. Journal of Bryology 28: 283-292.
  22. Hedderson, T.A. & T.L. Blockeel. 2006. Oncophorus dendrophilus a new moss species from Cyprus. Journal of Bryology. 28:357-359.
  23. Klak, C, T.L. Nowell & T.A. Hedderson. 2006. Phylogeny and revision of Brownanthus and its close allies Aspazoma and Dactylopsis (Aizoaceae) based on morphology and four DNA regions. Kew Bulletin 61: 353-400.
  24. P.V. Bruyns, R. Mapaya & T.A. Hedderson 2006. A new subgeneric classification for Euphorbia (Euphorbiaceae) in southern Africa based on ITS and psbA-trnH sequence data.. Taxon 55: 397-420.
  25. Bruyns, P.V., T.L. Nowell & T.A. Hedderson. 2005. A revision and phylogenetic analysis of Stapeliopsis (Apocynaceae). Botanical Journal of the Linnean Society 148: 125-155.
  26. Simmons, R.E., M.A. Du Plessis & T.A. Hedderson. 2005. Seeing the woodhoopoe for the trees: should we abandon Namibia's Violet Woodhoopoe Phoeniculus damarensis as a species? Ibis 147: 222-224.
  27. Klak, C., G. Reeves & T.A. Hedderson. 2004. Unmatched tempo of evolution in southern African ice plants. Nature 427: 63-65.
  28. Frahm, J.-P. & T. A. Hedderson. 2004. New and interesting Campylopus records from South Africa. Tropical Bryology 25 111-115.
  29. Hyvonen, J., S. Koskinen, G.L. Smith-Merrill, T.A. Hedderson & S. Stenroos. 2004. Phylogeny of the Polytrichales (Bryophyta) based on simultaneous analysis of molecular and morphological data. Molecular Phylogenetics and Evolution 31: 915-928.
  30. Hedderson, T.A., D. Murray, C.J. Cox & T.L. Nowell. 2004. Evolutionary relationships of the haplolepideous mosses inferred from rps4 gene sequences. Systematic Botany 29: 29-41.
  31. Klak, C., A. Khunou, G. Reeves & T.A. Hedderson. 2003. A phylogenetic hypothesis for the Aizoaceae based on four plastid DNA regions. American Journal of Botany 90:1433-1445.
  32. Hedderson, T.A. J.B. Letts & K. Payne. 2003. The rare thatch moss, Leptodontium gemmascens, on the Holnicote Estate, Somerset, UK: distribution and abundance in relation to roof variables. Lindbergia: 28:113-119.
  33. Klak, C., T.A. Hedderson & H.P. Linder. 2003. A molecular systematic study of the Lampranthus - group (Aizoaceae) based on the chloroplast trnL-trnF, and nuclear ITS and 5S NTS sequence data. Systematic Botany: 28:70-85.
  34. Hedderson, T.A. J.B. Letts & K. Payne. 2003. Bryophyte diversity and community structure on thatched roofs of the Holnicote Estate, Somerset. Journal of Bryology 25: 49-60.
  35. Cox, C.J. & T.A. Hedderson. 2003. Phylogenetic patterns within the moss family Bryaceae based on chloroplast DNA evidence. Journal of Bryology 25: 31-40.
  36. Caddick, L.R., P.J. Rudall, P. Wilkin, T.A.J. Hedderson & M.W. Chase. 2002. Phylogenetics of Dioscoreales based on combined analyses of morphological and molecular data. Botanical Journal of the Linnean Society 138: 123-144.
  37. Caddick, L.R., P. Wilkin, P.J. Rudall, T.A. Hedderson & M.W. Chase. 2002. Yams reclassified: a recircumscription of Dioscoreaceae and Dioscoreales. Taxon 51: 103-114.
  38. Hedderson, T.A.J. 2001. Molecular phylogenetic perspectives on conservation priorities. In: Jackson, A. and Hodgetts, N. G. (eds.) The ex situ conservation of bryophytes - developing a UK strategy. Royal Botanic Gardens Kew, London. (in press).
  39. Goffinet, B, C.J. Cox, A.J. Shaw, and T.A. Hedderson. 2001. The Bryophyta (Mosses): Systematic and evolutionary inferences from a rps4 gene (cpDNA) phylogeny. Annals of Botany 87: 191-208.
  40. Hedderson, T.A. L. Soderstrom & G.R. Brassard. 2001. Hepaticae of the Torngat Mountains, northern Labrador, Canada. Lindbergia 26:143-156.
  41. Baker, W.J., T.A. Hedderson & J.W. Dransfield. 2000. Molecular phylogenetics of subfamily Calamoideae (Palmae) based on nrDNA ITS and cpDNA rps16 intron sequence data. Molecular Phylogenetics and Evolution 14: 195-217
  42. Baker, W.J., T.A. Hedderson & J.W. Dransfield. 2000. Molecular phylogenetics of Calamus and related rattan genera based on 5s nrDNA spacer sequence data. Molecular Phylogenetics and Evolution 14: 218-231.
  43. Baker, W.J., J.W. Dransfield & T.A. Hedderson. 2000. Phylogeny, character evolution, and a new classification of the Calamoid palms. Systematic Botany: 25: 297-322.
  44. Cox, C., B. Goffinet, A. E. Newton, A. J. Shaw, & T.A. Hedderson. 2000. Phylogenetic relationships among the diplolepidous-alternate mosses (Bryidae) inferred from nuclear and chloroplast DNA sequences. The Bryologist 103: 224-241.
  45. Goffinet, B. & T.A. Hedderson. 2000. Evolutionary biology of the Bryopsida (Mosses); a synthesis. The Bryologist 103: 184-186
  46. Laaka-Lindberg, S., T.A. Hedderson & R.E. Longton. 2000. Rarity and reproductive characters in the British hepatic flora. Lindbergia: 25: 78-84.
  47. Longton, R.E. & T.A. Hedderson. 2000. What are rare species and why conserve them? Lindbergia: 25: 53-61.
  48. Newton, A.E, C.J. Cox, J.G. Duckett, J. Wheeler, B. Goffinet, T. Hedderson & B.D. Mishler. 2000. Evolution of the major moss lineages; phylogenetic analyses based on multiple gene sequences and morphology. The Bryologist: 103: 187-211.
  49. Searle, R. & T.A. Hedderson. 2000. A preliminary phylogeny of the Hedychieae (Zingiberaceae) based on ITS sequences of the nuclear rRNA cistron, pp. 710-718 in Wilson, K.L. & D.A. Morrison (eds.), Monocots; Systematics and Evolution. CSIRO, Collingwood.
  50. Reese, W.D. & T.A. Hedderson. 1999. Two species of Grimmia new to Louisiana. Evansia 16: 112.
  51. Hedderson, T.A., C.J. Cox & J.G. Gibbings. 1999. Phylogenetic relationships of the Wardiaceae (Musci): evidence from 18s rRNA and rps4 gene sequences. Bryologist 102: 26-31
  52. Baker, W.J., C.B. Asmussen, S.C. Barrow, J. Dransfield & T.A. Hedderson. 1999. A phylogenetic study of the palm family (Palmae) based on chloroplast DNA sequences form the trnL-trnF region. Plant Systematics and Evolution 219: 111-126.
  53. Cox, C.J. & T.A. Hedderson. 1999. Phylogenetic relationships among the ciliate arthrodontous mosses: evidence from chloroplast and nuclear DNA sequences. Plant Systematics and Evolution 215: 119-239
  54. Compton, J.A. & T.A. Hedderson. 1999. A morphometric analysis of the Actaea simplex (Ranunculaceae) complex. Botanical Journal of the Linnean Society: In the presses
  55. Dick, M.W., M.C. Vick, J.G. Gibbings, T.A. Hedderson & C.C. Lopez-Lastra. 1999. 18s rDNA for species of Leptolegnia and other Peronosporomyces: justification for the subclass taxa Saprolegniomycetidae and Peronosporomycetidae and division of the Saprolegniaceae sensu lato into the families Leptolegniaceae and Saprolegniaceae. Mycological Research 103: 1119-1131.
  56. Hedderson, T.A.J., R.L. Chapman & C. J. Cox. 1998. Bryophytes and the origins and diversification of the land plants: new evidence from molecules, pp. 65-78. In J. W. Bates et al (eds.) Bryology for the Twenty-First Century. Maney Publishing and British Bryological Society, Leeds.
  57. Vitt, D. H., B. Goffinet & T. A. Hedderson. 1998. Ordinal level classification of the mosses: questions and answers for the 1990's, pp. 113-123. In J. W. Bates et al (eds.) Bryology for the Twenty-First Century. Maney Publishing and British Bryological Society, Leeds.
  58. Hyvonen, J., T.A. Hedderson, G.L. Smith, J.G. Gibbings & S. Koskinen, 1998. On phylogeny of the Polytrichales. The Bryologist 101: 489-504
  59. Compton, J.A. & T.A. Hedderson. 1997. A morphometric analysis of the Cimicifuga foetida L. complex (Ranunculaceae). Botanical Journal of the Linnaean Society 123: 1-23
  60. John, P., T. Iturriagagoitia-Buena, V. Lay, P.G.Thomas, T.A. Hedderson, A.G. Prescott, E.J. Gibson & C.J. Schofield. 1997. 1-aminocyclopropane-1-carboxylate oxidase: molecular structure and catalytic function. Pp 15-21 in Kanellis, A.K. (ed.) Biology and Biotechnology of the Plant Hormone Ethylene. Kluwer, Dordrecht.
  61. Hedderson, T.A., R.L. Chapman & W.L. Rootes. 1996. Phylogenetic relationships of bryophytes inferred from nuclear-encoded rRNA gene sequences. Plant Systematics and Evolution 200: 213-224
  62. Abu Sbaih, H., S.L. Jury & T.A. Hedderson. 1996. A cladistic investigation and key to the species of the genus Orobanche L. sect. Trionychon Wallr. Pp. 136-142 in Moreno, M.T., J.I Cubero, D. Berner, D. Joel, L.J. Musselman and C. Parker (eds). Advances in Parasitic Plant Research. Novograf, Sevilla.
  63. Hedderson, T.A. & R.E. Longton. 1996. Life history variation in mosses: water relations, size and phylogeny. Oikos 77: 31-43
  64. Hedderson, T.A. & R.E. Longton. 1995. Patterns of life history variation in the Funariales, Polytrichales, and Pottiales. Journal of Bryology 18: 639-675
  65. Hedderson, T.A. & G.R. Brassard. 1992. Tetrodontium repandum (Funck) Schwaegr. & Seligeria diversifolia Lindb. discovered in Arctic Canada. The Bryologist 95: 443-444.
  66. Belland, R.J., W.B. Schofield & T.A. Hedderson. 1992. Bryophytes of Mingan Archipelago National Park Reserve, Quebec: a boreal flora with arctic and alpine components. Canadian Journal of Botany 7: 2207-2222.
  67. Hedderson, T.A. 1992. Rarity at range limits; dispersal capacity and habitat relationships of rare extraneous moss species in a boreal Canadian National Park. Biological Conservation 59: 113-120.
  68. Hedderson, T.A. & G.R. Brassard. 1992. Encalypta affinis ssp. macounii and E. brevipes new to eastern North America from the Torngat, northern Labrador, Canada. The Bryologist 95: 31-32.
  69. Hedderson, T.A. & A.S. Harold. 1991. Plagiobryum duthiei, a new moss species from Nepal. Lindbergia 16: 51-54.
  70. Hedderson, T.A. 1991. Floristics and phytogeography of Borup Fiord, Northern Ellesmere Island. Chapter 5. In W. Hankinson (ed.) Report of the Joint Service Expedition to Borup Fiord, Ellesmere Island. British Ministry of Defense.
  71. Hedderson, T.A. & G.R. Brassard. 1990. Microhabitat relationships of five co-occurring saxicolous mosses on cliffs and scree slopes in eastern Newfoundland. Holarctic Ecology 13:134-142.
  72. Hedderson, T.A. 1989. Plagiobryum hultenii (Ochi & H.Perss.) Hedderson stat. nov.; a re-evaluation of an endemic Japanese moss. Lindbergia 15:161-165.
  73. Brassard, G.R., M. Favreau, & T.A. Hedderson. 1989. New and additional moss records from Newfoundland, IX. The Bryologist 92: 473-478.
  74. Hedderson, T.A. 1988. The bryogeographical significance of the Torngat Mountains, northern Labrador. pp 312-326 In W.P. Adams & P.G. Johnson (eds.). Proceedings of the National Student Conference on Northern Studies. Association of Canadian Universities for Northern Studies, Ottawa.
  75. Brassard, G.R. & T.A. Hedderson. 1987. Grimmia torngakiana sp. nov. from northern Labrador. Memoirs of the New York Botanical Garden 45:216-218.
  76. Hedderson, T.A. 1986. A naturally occurring moss hybrid between Orthotrichum gymnostomum and O. obtusifolium from Newfoundland, Canada. The Bryologist 89:165-167.
  77. Hedderson, T.A. & G.R. Brassard. 1986. The bryophytes of Nachvak, northern Labrador, with additional records from Saglek. Canadian Journal of Botany 64: 2028-2036.
  78. Brassard, G.R. & T.A. Hedderson. 1983. The distribution of Mielichoferia macrocarpa, a North American endemic moss. The Bryologist 86: 271-273.
  79. Hedderson, T.A., G.R. Brassard, & R.J. Belland. 1982. New or additional moss records from Newfoundland VIII. The Bryologist 85: 442-443.