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The genera of Cactaceae |
This package is generated from a DELTA database (Dallwitz 1980; Dallwitz, Paine, and Zurcher 1993). It includes an interactive key using the Intkey app (Dallwitz, Paine, and Zurcher 1995, 2000). Subsidiary material such as descriptions, illustrations, and references, can be accessed through Intkey, and is also directly available on the Web.
The inclusion of comparative data on anatomy, physiology, embryology, pollen morphology, and phytochemistry allows physiologists, biochemists and geneticists to select taxonomically balanced samples for experimental work.
Corrections and other input are welcome and will be acknowledged. Alternatively, the complete Delta data set can be donated for research or teaching purposes, or to any person or organization interested in developing it further.
The References file lists sources of the comparative data. The morphological data mostly represent compilation from the keys and descriptions in the classic works of Britton and Rose (1919–1923), Borg (1970) and Backeberg (1976) (all requiring nomenclatural changes); and Anderson’s 2001 publication. The latter provides comprehensive and relatively up-to-date generic descriptions, and a classification into subfamilies and tribes conforming with that of The International Cactaceae Systematics Group (ICSG) at that date, but no keys.
Intkey facilitates identifications within geographical regions, or of fragmentary material, fossils, etc. It is also easy to obtain lists of genera exhibiting or lacking particular features or combinations of features; to cross reference attributes with geographical distributions and proposed classifications; to obtain lists of genera for which information on particular features is lacking; to locate synonyms; and to compare rival classifications, with statistical details of character-state distributions within groups. For example, exploration of the ISCG classification (Anderson 2001) confirms that some tribes of Cactoideae (Cereae/Trichocereae/Notocacteae, Rhipsalideae/Pachycereeae) are indistinguishable in terms of the available data. The ‘error tolerance’ facility is especially valuable in this family, given the combination of difficulties over morphological interpretation and generic circumscriptions.
The images are mainly scans from Britton & Rose (1919–1923), and photos by Zoya Akulova (2007–2018) at calphotos.berkeley.edu. All the scans carry the original legends, but current names are also given.
For further illustrations, see Anderson (2001), which includes photographs of representatives of all the genera.
22 November 2018