Permutation Group Theory; infinite permutation groups, the normal subgroup structure of Permutation Groups, Conjugacy classes, Subgroups of small index.
Bruyns, P.V. Results on subgroups of the group of homeomorphisms of the rational numbers.Quaestiones Mathematicae 11 (1988), 293-300.
Bruyns, P.V. & Rose, H. Amalgamation in certain small varieties. J. Korean Math. Soc. 26 (1989), 83-95.
Bruyns, P.V. Approximate centralizers in the group of homeomorphisms of the rational numbers. Archiv der Mathematik 54 (1990), 14-17.
Rose, H. & Bruyns, P.V. Varieties with cofinal sets. Proceedings of the American Mathematical Society 111 (1991), 833-840
Bruyns, P.V. The number and size of orbits of some permutation groups. Quaestiones Mathematicae 14 (1991), 355-360.
Rose, H., Naturman, C. & Bruyns, P.V. Amalgamation in the pentagon variety. Algebra Universalis 29 (1992), 303-322.
Bruyns, P.V. Conjugacy classes in the group of automorphisms of the rationals. Quaestiones Mathematicae 24 (2001) 237-246.
Aloe bruynsii, from the mountains of south-east Madagascar.
Haworthia bruynsii, a small succulent
Aloe bruynsii in flower.
Key Research Categories: Systematics, Molecular Systematics and the Reconstruction of Phylogenies; Biodiversity in the arid and semi-arid regions of Africa and the Arabian Peninsula; Speciation and the Time-Scale of the evolution of Biodiversity.
The main thrust is the Systematics of the different families of Succulent Plants. Southern Africa has the highest diversity of succulents in the world and I am particularly interested in the families Apocynaceae and Euphorbiaceae, with involvement also in the Aizoaceae, Crassulaceae and Didieriaceae. Using the newly developed techniques of analyzing data from DNA, we have reconstructed robust hypotheses on the evolution of several groups in the Aizoaceae, Apocynaceae and Euphorbiaceae. These new phylogenetic hypotheses have also been used to replace outdated classifications in a wide range of African succulent plant groups with new ones which reflect our much greater insight into their relationships and evolution. Our work on Caralluma (Apocynaceae) and Euphorbia revealed previously unknown scenarios for the radiation of these groups in Africa, the Arabian Peninsula and India and we have used dating techniques to show that many are recent and due to long-distance dispersal. The paper Endress & Bruyns (2000) led to a revival of interest in the Apocynaceae, with a new, much expanded concept of the family. It formed the basis for special subconferences on the Apocynaceae at the 14th, 15th and 16th International Botanical Conferences.
Major accounts of the Apocynaceae, Crassulaceae and Euphorbiaceae were contributed for the Cape Plants (Goldblatt & Manning 2000; Manning & Goldblatt,in press) and for the Succulent Karoo Flora (Snijman, in press), both SANBI projects. I have also contributed an account of the Apocynaceae for the Flora of the Arabian Peninsula (Royal Botanic Gardens, Edinburgh).
Ongoing revisional work on Euphorbia forms part of the Planetary Biodiversity Initiative Project, co-ordinated by Prof. P.E. Berry, University of Michigan, USA.
Many of the groups that I have studied are poorly known and rarely recorded. In order to improve the herbarium record, I have been very active in field-work, which has involved exploring many poorly-known areas in Angola, Ethiopia, Namibia, South Africa and Yemen, in the process making some 12000 herbarium records (mostly housed in BOL, E and NBG), mainly of succulent plants. During this, I was fortunate enough to have discovered some 50 new species, of which 11 have been named after me by specialists in the groups concerned.
Bruyns, P.V. 2000. Euphorbia. In Goldblatt, P. & Manning, J.M. (eds.), Cape Plants. Strelitzia 9.
Bruyns, P.V. 2000. Apocynaceae. In Goldblatt, P. & Manning, J.M. (eds.), Cape Plants. Strelitzia 9.
Bruyns, P.V. 2002. A Monograph of Orbea and Ballyanthus (Apocynaceae -- Asclepiadoideae-- Ceropegieae). Systematic Botany Monographs 63: 1-196.
Bruyns, P.V. & Miller, A.G. 2004. Asclepiadaceae In Miller, A.G. & Morris, M. (eds.) Ethnoflora of the Soqotra Archipelago. Royal Bot. Gardens, Edinburgh.
Bruyns, P.V. 2005. Stapeliads of southern Africa and Madagascar. 2 Vols. Umdaus Press, Hatfield, South Africa. ISSN 1-919766-33-2/34-0
Bruyns, P.V. 2010. Towards the phylogeny of the succulent Euphorbiaceae. Pp. 37--58. In: Metzing, D. & Jürgens, N. (eds) Phylogeny of Succulent Plant Families (Schumannia 6; Biodiversity & Ecology 3). ISBN 978-3-89995-752-5. Universitätsverlag Isensee, Oldenburg, Germany.
The very dissected and arid northern Richtersveld of South Africa, here viewed from a steep slope east of Rosh Pinah in Namibia. The Orange River flows through the middle of the picture.
Endress, M.E. & Bruyns, P.V. 2000. A revised Classification of the Apocynaceae s.l.. Bot. Review (Lancaster) 66: 1-56. [This paper has been cited over 200 times! ]
Bruyns, P.V. 2000. Phylogeny and Biogeography of the stapeliads. 1. Phylogeny. Plant Syst. Evol. 221: 199-226.
Bruyns, P.V. 2000. Phylogeny and Biogeography of the stapeliads. 2. Biogeography. Plant Syst. Evol. 221: 227-244.
Bruyns, P.V. 2000. Baynesia, a new genus of stapeliad from the north-westernmost corner of Namibia. Novon 10: 354-358.
Bruyns, P.V. & Miller, A.G. 2002. Socotrella, a new genus of stapeliad (Apocynaceae -- Asclepiadoideae) from the island of Socotra. Novon 12: 330-333.
Bruyns, P.V. 2003. Three new succulent species of Apocynaceae (Asclepiadoideae) from southern Africa. Kew Bull. 58: 427-435.
Bruyns, P.V. 2003. A revision of Astephanus (Apocynaceae). Kew Bull. 58: 867-887.
Bruyns, P.V. & Dold, A.P. 2003. A new subspecies of Brachystelma from the Eastern Cape, South Africa. Bothalia 33: 105-6.
Granite domes near Ribáuè in Nampula Province, Moçambique, at about 1 200 m, covered with succulants despite the high annual rainfall of nearly 1 500 mm. Here one sees a species of Aloe, Euphorbia mlanjeana and Kalanchoe elizae.
Bruyns, P.V. & Klak, C. 2004. Revision of the Madagascan endemic Stapelianthus (Apocynaceae) based on molecular and morphological characters. Ann. Missouri Bot. Gard. 91: 410-437.
Bruyns, P.V. 2004. New species in Echidnopsis and Secamone and new records of Ceropegia (Apocynaceae) from Socotra. Edinburgh J. Bot. 61: 7-19.
Bruyns, P.V., Nowell, T. & Hedderson, T. 2005. A revision and phylogenetic analysis of Stapeliopsis (Apocynaceae). J. Linn. Soc., Bot. 148: 125-155.
Bruyns, P.V., Mapaya, R. & Hedderson, T. 2006. A new subgeneric classification for Euphorbia (Euphorbiaceae) based on molecular data. Taxon 55: 397-420.
Bruyns, P.V. & Klak, C. 2006. A Systematic study of the old world genus Fockea (Apocynaceae - Asclepiadoideae). Ann. Missouri Bot. Gard. 93: 535-564.
Bruyns, P.V. 2006. Three new species of Euphorbia (Euphorbiaceae) and Brachystelma (Apocynaceae) from South Tropical Africa. Novon. 16: 444-447.
Bruyns, P.V. 2006. A new species of Brachystelma (Apocynaceae) from South Tropical Africa. Novon 16: 442-443.
Klak, C., Bruyns, P.V. & Hedderson, T. 2007. A phylogeny and new classification for Mesembryanthemoideae (Aizoaceae). Taxon 56: 737-756.
Bruyns, P.V. 2007. A new species of Huernia (Asclepiadoideae-Ceropegieae) from southern Angola. Bothalia 37: 23-25.
Bruyns, P.V. 2008. A new species of Huernia (Apocynaceae-Ceropegieae) from Angola. Bothalia 38: 83-85.
Bruyns, P.V. & Miller, A.G. 2009. Lectotypification of some Arabian Apocynaceae. Edinburgh J. Bot. 66: 97--101.
Bruyns, P.V. 2009. Three new species of Brachystelma (Apocynaceae, Asclepiadoideae, Ceropegieae) from South Tropical and Southern Africa. Novon 19: 18--22.
Bruyns, P.V. 2009. A new species of succulent Euphorbia from southern Angola. Bothalia 39: 219--221.
Bruyns, P.V. & Klak, C. 2009. The rediscovery of Schizostephanus gossweileri and its phylogenetic position. S. African J. Bot. 75: 532--536.
Venter, H.J.T., Verhoeven, R.L. & Bruyns, P.V. 2009. Morphology and Taxonomy of Mondia (Apocynaceae: Periplocoideae) S. African J. Bot. 75: 456--465.
Bruyns, P.V. 2010. A new species of Caralluma (Apocynaceae-Asclepiadoideae-Ceropegieae) from the Yemen. S. African J. Bot. 76: 249--251.
Bruyns, P.V. 2010. Huernia humpatana (Apocynaceae), a new species from southern Angola. S. African J. Bot. 76: 585--587.
Bruyns, P.V., Al-Farsi, A. & Hedderson, T. 2010. Phylogenetic relationships of Caralluma R. Br. (Apocynaceae). Taxon 59: 1031--1043.
Bruyns, P.V. 2010. A new name for Euphorbia chamaeclada from Angola. Bothalia 40: 178.
Bruyns, P.V. 2011. A new species of Sarcostemma (Apocynaceae-Asclepiadoideae-Asclepiadeae) from Yemen. South African Journal of Botany 77: 801--804.
Bruyns, P.V., Klak, C. & Hanàcek, P. 2011. Age and diversity in Old World succulent species of Euphorbia (Euphorbiaceae). Taxon 60: 1717-1733.
Klak, C. & Bruyns, P.V. 2012. Phylogeny of the Dorotheantheae (Aizoaceae), a tribe of succulent annuals. Taxon 61: 293--307.
Bruyns, P.V. 2012. Nomenclature and typification of southern African species of Euphorbia. Bothalia 42: 217--245.
Sarcostemma oresbium, a delicate species with pendulous flowers discovered in the mountains shown above of Northern Mossambique.