Question: Which genus has more species Graptopetalum or Tanakaea ?

Context paragraphs:
Tanakaea: Tanakaea radicans or the Japanese foam flower, is a member of the Saxifrage family native to Japan, and is the sole species in the genus Tanakaea.  It is named after the Japanese botanist Tanaka Yoshio.  It was initially described by Ludovic Savatier and Adrien René Franchet.

Graptopetalum: Graptopetalum (leatherpetal) is a plant genus of the family "Crassulaceae".  They are perennial succulent plants and native to Mexico and Arizona.  They grow usually in a rosette.  There are around 19 species in this genus.

Graptopetalum macdougallii: Graptopetalum macdougallii is a plant belonging to the succulent genus "Graptopetalum".  It is native to Mexico.  It grows on shady rocks, or rarely as an epiphyte, at an altitude of 1200 – 2100 meters, geographically isolated from all other Graptopetalum species.

Supporting paragraphs: Graptopetalum Tanakaea
Answer: Graptopetalum