 However, since then it has been split into at least "Adromischus", "Dudleya", "Rosularia", and "Tylecodon", leaving probably less than two dozen species in "Cotyledon".Of these, about four are characteristically fynbos plants.Most plants in the genus, and those that used to be included in the genus "Cotyledon", are poisonous, even dangerously so.