The genus Neocinnamomum H. Liu is one of the most enigmatic groups in Lauraceae, with six species endemic to tropical to subtropical Asia. In the past Neocinnamomum was considered to be close to Cinnamomum. In contrast, recent molecular phylogenetic studies in Lauraceae have revealed novel but conflicting phylogenetic relationships for Neocinnamomum, and the previously suggested affinity with Cinnamomum was rejected.
Using psbA–trnH, trnK cpDNA regions, and the ITS nrDNA segment, XTBG Master candidate WANG Zhihua and his supervisor Prof. LI Jie conducted a phylogenetic analysis of Neocinnamomum by using the materials of five Neocinnamomum species and 15 species from the related genera in Lauraceae.
They found that Neocinnamomum was monophyletic. The compound thyrse seen in N. caudatum is reduced to the few- to many-flowered condensed inflorescences with a poorly defined branching system seen in most species, and ultimately to the 1-flowered inflorescence seen in N. atjehense. Neocinnamomum is more closely related to the genus Caryodaphnopsis than to the genus Cassytha. Caryodaphnopsis and Neocinnamomum may be the descendants of Laurasian Cretaceous Lauraceae. These analyses further suggest that Neocinnamomum may be one of the basal groups in Lauraceae.Their results, entitled “Phylogeny of the Southeast Asian endemic genus Neocinnamomum H. Liu (Lauraceae)”, reported in Plant Systematics and Evolution (2010) 290: 173-184.