Wood anatomy of the subfamily Crotonoideae (Euphorbiaceae s.s.) from India: systematic implications with special reference to the taxonomic delimitation of Givotia and Vernicia

The wood anatomy of 15 representative species belonging to 12 genera of nine tribes of the subfamily Crotonoideae (Euphorbiaceae) are comprehensively described with focus on systematic implications. In addition, ecological and evolutionary aspects are evaluated. An identification key to the species based on wood anatomical features is presented. The wood microstructure of the tribes was found to be considerably heterogeneous reflecting an unnatural classification of the subfamily. However, the results confirm the generic relationship within subtribe Aleuritinae and tribe Ricinodendreae. Vernicia and Givotia may be recognized based on wood anatomical and morphological characters. The tribes Micrandreae and Adenoclineae have considerable similarity in wood anatomy. The wood structure of the monogeneric tribes Trigonostemoneae and Geloneae idicate a close relationship with the tribe Crotoneae.