- Haworthia flowers – some comments as a character source, part 1
- Haworthia flowers – some comments as a character source, part 2
- Haworthia flowers – some comments as a character source, part 3
- Haworthia flowers – some comments as a character source, Appendix 5
- Haworthia flowers – some comments as a character source, Appendix 6
- Haworthia flowers – some comments as a character source, Appendix 7
- Haworthia flowers – some comments as a character source, Appendix 8
- Haworthia flowers – some comments as a character source, Appendix 9
- Haworthia flowers – some comments as a character source, Appendix 10
- A further report on Haworthia mirabilis in the Greyton area.