Durham E-Theses Studies in the genus gymnocalycium Swales, G.J How to cite: Swales, G.J (1975) Studies in the genus gymnocalycium, Durham theses, Durham University. Available at Durham E-Theses Online: http://etheses.dur.ac.uk/8889/ Use policy The full-text may be used and/or reproduced, and given to third parties in any format or medium, without prior permission or charge, for personal research or study, educational, or not-for-prot purposes provided that: • a full bibliographic reference is made to the original source • a link is made to the metadata record in Durham E-Theses • the full-text is not changed in any way The full-text must not be sold in any format or medium without the formal permission of the copyright holders. Please consult the full Durham E-Theses policy for further details. Academic Support Oce, Durham University, University Oce, Old Elvet, Durham DH1 3HP e-mail:
[email protected] Tel: +44 0191 334 6107 http://etheses.dur.ac.uk STUDIES IN THE GENUS GYMNOCALYCIUM G. J. SWALES The copyright of this thesis rests with the author. No quotation from it should be published without his prior written consent and information derived from it should be acknowledged. A Thesis submitted for the degree of Master of Science in the University of Durham September 1975 1 Studies in the genus GYMNOCALYCIUM Pfeiffer A critical survey of the literature, especially original descriptions, of two of the major groups within the genus; an attempt to define the distribution of these species as far as it is known; a tentative suggestion for a better regrouping of the species, and photographs, where available, of examples from these groups at present in cultivation in my reference collection.