autogamy vs self-fertilisation

autogamy and self-fertilisation both are nouns.

Word	Noun	Adjective	Verb	Adverb
autogamy	Yes	No	No	No
self-fertilisation	Yes	No	No	No

As nouns, self-fertilisation is a hypernym of autogamy; that is, self-fertilisation is a word with a broader meaning than autogamy:

autogamy: self-fertilization in plants
self-fertilisation: fertilization by the union of male and female gametes from the same individual

Other hypernyms of autogamy include self-fertilization.

autogamy (noun)	self-fertilisation (noun)
self-fertilization in plants	fertilization by the union of male and female gametes from the same individual