The seed structure and taxonomic relationships of Hypseocharis Remy

Hypseocharis has a bitegmic, crassinucellate and anatropous ovule. Shortly after fertilization the ovule becomes campylotropous by a bulge formed by the inner integument at the raphal side. The seed coat is characterized by a crystalliferous endotesta and an exotegmen consisting of stellately lobed cells. The seed structure corresponds to that of the Geraniaceae s.s. The loculicidal capsule of Hypseocharis does not show the specialized method of dispersal of the beaked fruits of Geraniaceae s.s. The andine genus Hypseocharis may be a relic of the ancestors of modern Geraniaceae that lived in the Gondwana continent before the separation of South America and Africa. This study indicates that Hypseocharis has to be placed in Geraniaceae, not in Oxalidaceae.