Aylostera diersiana (Rausch) Mosti & Papini
Regarded by some as yet another form of Aylostera pygmaea. Although the ranges of A. pygmaea and A. diersiana overlap, to my knowledge no hybrids have been found in places where they occur together. A diersiana can look very like a yellow-flowered A. pygmaea, but the latter usually has warm tones to the colour- golds or oranges. A. diersiana, at least on the upperside, is usually a cool yellow, and the style and stigmas have greenish tones (rather than the reddish or pinkish of A. pygmaea). There are also internal anatomical differences in the flower tube (for which, see the descriptions). Found to be distinct enough to be given specific status by Mosti & Papini (2011).
Two varieties were described by Rausch: var. diersiana, and var. atrovirens. After Mosti & Papini (2011) these are now regarded as subspecies.
The original description of both subspecies is here.
Plants of this species in the collection include:
Aylostera diersiana coll. Riesner