Hoya lithophytica

This species was described in 2012 and while it is rare in habitat, it is rather easy and flowerful in cultivation. 

Each inflorescence has 5–15 flowers with a white corolla (with a pinkish shade) and bright purple-red, fleshy coronal scales inside.

Hoya lithophytica is known from one location in the Tak Province of Thailand, at abou 850 m asl. There it grows in scrub and open forest, usually on exposed limestone cliffs or outcrops, scrambling on rock and branches.