Question: Which genus has the most species, Stachyurus or Buckinghamia?

Context paragraphs:
Buckinghamia: Buckinghamia is a genus of only two known species of trees, belonging to the plant family Proteaceae.  They grow naturally only (endemic) in the rainforests of the wet tropics region of north eastern Queensland, Australia.  The ivory curl flower, "B. celsissima", is the well known, popular and widely cultivated species in gardens and parks, in eastern and southern mainland Australia, and additionally as street trees north from about Brisbane.  The second species, "B. ferruginiflora", was only recently described in 1988.

Stachyurus: Stachyurus is the only genus in the flowering plant family Stachyuraceae, native to the Himalayas and eastern Asia.  They are deciduous shrubs or small trees with pendent racemes of 4-petalled flowers which appear on the bare branches before the leaves.  The plants have leaves with serrate margins.  Stachyuraceae contains a single genus with eight species.

Supporting paragraphs: Stachyurus Buckinghamia
Answer: Stachyurus