Wikipedia
Mellissia is a genus in the family Solanaceae with a single species, Mellissia begoniifolia (Saint Helena Boxwood), that is endemic to the island of Saint Helena. It was named by Joseph Dalton Hooker in honour of John Charles Melliss, a 19th-century engineer and amateur naturalist who worked on Saint Helena.
Mellissia begoniifolia is notable for the subcampanulate calyx which encloses the white corolla, and is strongly accrescent in fruit, somewhat like the "Chinese lantern" genus, Physalis. However, it is in fact closely related to the genus Withania.
The plant was long thought to be extinct but a small population was discovered in 1998 by Stedson Stroud. As of 2011, it was considered "effectively extinct in the wild" by experts at Kew Botanical Garden because there were no longer any flowering plants left in the wild. Only one adult plant was left by 2010, and it was under extreme stress due to drought and pests. That plant died, but some seedlings sprouted from 2011 rains. The survival of the seedlings is questionable.