Lasianthus is a large genus of the Rubiaceae with more than 180 species, predominantly in the Old World. Lasianthus species are usually present in large numbers in the tropical forests of Asia and may therefore represent an ecologically important element. The species of Lasianthus also show interesting distribution patterns, which are of special interest for the study of the biogeography of tropical Asia and of prevailing speciation models in tropical rainforests.
About 140 Lasianthus species names and numerous varieties were published based on Malesian collections before 1938 . Since 1950, many more specimens from the Malesian region have been collected, but a synopsis on the genus for Malesia has not been made so far. Therefore, a revision of Lasianthus from Malesia is most needed.
Prof. Zhu Hua of Xishuangbanna Tropical Botanical Garden (XTBG) and his colleagues from the Netherlands made a taxonomic revision on the genus Lasianthus, based on herbarium collections.
They recognized 131 species from the Malesian region, of which 41 species, 3 subspecies and 3 varieties were described as new, and 3 new combinations were made for varieties. 22 species names and 15 variety names were reduced to synonyms. 10 species names and 2 varieties were treated as dubious mainly because their types could not be traced. Additionally, 11 species were excluded from Lasianthus.
All species were described and a key to Malesian Lasianthus was given.
The study entitled “A taxonomic revision of the Malesian species of Lasianthus (Rubiaceae)” has been published in Blumea – Biodiversity, Evolution and Biogeography of Plants, 57 (1): 1-102, http://dx.doi.org/10.3767/000651912X652012
Blumea - Biodiversity, Evolution and Biogeography of Plants