FlytrapCare Carnivorous Plant Forums

Yeah, as stated the Queensland sisters, pygmy sundews and tuberous Drosera aren't self fertile. I believe that the petiolaris complex (excluding drosera banksii) and South American dews aren't self fertile either, though I'm not sure about Drosera magnifica. The Drosera indica complex is self-fertile.

The main reason that self-incompatibility is favored over asexual reproduction, is because in areas of the world that undergo change rapidly, mutation is advantageous. This is because through sexual reproduction through multiple plants, the difference in dimorphism displayed by the seedlings allows for a higher chance that one of the seedlings is better suited for the environment than its siblings or parents. In short in areas of the world that undergo rapid change reproduction by seeds is favored because of the higher rate of adaptation/mutation present in seed grown plants.

Self compatibility is favorable in regions that change slower over time as asexual reproduction allows the plant in question to quickly spread over the environment it is used to so the large population will withstand change by brute force and lineage.

These definitions also depend on the type of plant in question as cacti do both in deserts.

Probably a good rule of thumb is if it's easy, common and cheap, it's probably self-fertile. For instance: spatulata, capillaris, natalensis, and burmannii.

Many South American drosera are self fertile. Some such as graomogolensis and ascendens seem to not be (definitely missed a bunch). Annuals and North American temperate species will generally be SC as well as a lot of South African species, excluding a few. The reason behind self-compatibility is not 100% uncovered to my knowledge, but for example, annuals will need to be able to propagate by seed because they die at the end of the growing season and need a way to consistently reset