Monograph of Omphalocarpum (Sapotaceae)
Omphalocarpum sp. (Sapotaceae) Ebo Forest, Cameroon
This project aims to monograph the genus and produce a definitive guide to the taxa within, to be published in Kew Bulletin.
The genus Omphalocarpum P.Beauv. (Sapotaceae), confined to Guineo-Congolian Africa probably consists of about six species, although 38 names have been validly published. These 20-30 m tall rainforest trees are most famous for their woody-walled, pumpkin-sized, trunk-borne, elephant-dispersed fruits.
The main difficulty is species delimitation, and this has been compounded by different approaches taken by different treatments. The genus was studied in the early part of the 20th century by De Wildeman who named, and subsequently illustrated, collections from the “Congo”. Owing to the small number of collections (frequently with either fruit or flowers – not both), he used character variation to delimit species. Many of his new taxa were based on seed differences, such as the direction in which the “beak” is pointed, or the prominence of the furrow along the seed surface. Unfortunately seeds are very variable, even between those found in different fruits from the same tree. In the years since his work there have been many more collections and attempts have been made to reduce many of De Wildeman's names in various floral treatments. It is now time to look at the genus across its entire distribution.