''Physostigma'' is a genus of

flowering plant Flowering plants are plants that bear flowers and fruits, and form the clade Angiospermae (). The term angiosperm is derived from the Ancient Greek, Greek words (; 'container, vessel') and (; 'seed'), meaning that the seeds are enclosed with ...

s in the family

Fabaceae Fabaceae () or Leguminosae,International Code of Nomen ...

. It includes five species of erect or climbing herbs and subshrubs native to sub-Saharan Africa. They grow in tropical swamp and riverine vegetation and seasonally-dry forest, open woodland, and grassland in the Guineo-Congolian and

Zambezian region The Zambezian region is a large biogeographical region in Africa. The Zambezian region includes woodlands, savannas, grasslands, and thickets, extending from east to west in a broad belt across the continent. The Zambezian region lies south of th ...

s. The genus belongs to subfamily

Faboideae The Faboideae are a subfamily of the flowering plant family Fabaceae or Leguminosae. An acceptable alternative name for the subfamily is Papilionoideae, or Papilionaceae when this group of plants is treated as a family. This subfamily is widely ...

. Species in the genus include: * '' Physostigma coriaceum'' Merxm. * '' Physostigma cylindrospermum'' (Welw. ex Baker) Holmes * '' Physostigma laxius'' Merxm. * '' Physostigma mesoponticum'' Taub. * ''

Physostigma venenosum ''Physostigma venenosum'', the Calabar bean or ordeal bean, is a leguminous plant, Endemic to tropical Africa, with a seed poisonous to humans. It derives the first part of its scientific name from a curious beak-like appendage at the end of the ...

'' Balf.

References

Phaseoleae Taxa named by John Hutton Balfour Fabaceae genera Flora of the Afrotropical realm {{Phaseoleae-stub