Orobanche amethystea subsp. castellana (Reut.) Rouy is accepted at species level as Orobanche castellana Reut.:

https://powo.science.kew.org/taxon/urn:lsid:ipni.org:names:2900902-4

The autonym Orobanche amethystea subsp. amethystea is therefore no longer valid:

https://powo.science.kew.org/taxon/urn:lsid:ipni.org:names:662105-1