What is "holarrhena"

Holarrhena is a genus of plant in the Apocynaceae family first described as a genus in 1810. It is native to tropical and southern Africa as well as south, east, and southeast Asia. the World Checklist of Selected Plant Families recognises 5 species:

• Holarrhena congolensis Stapf - Zaïre
• Holarrhena curtisii King & Gamble - Indochina
• Holarrhena floribunda ( G.Don) T.Durand & Schinz - western + central Africa
• Holarrhena mitis ( Vahl) R.Br. ex Roem. & Schult. - Sri Lanka
• Holarrhena pubescens Wall. - eastern, southern + central Africa; Indian Subcontinent, Indochina, parts of China