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

Abstract

Th e 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 identifi cation key to the species based on wood anatomical features is presented. Th e wood microstructure of the tribes was found to be considerably heterogeneous refl ecting an unnatural classifi cation of the subfamily. However, the results confi rm the generic relationship within subtribe Aleuritinae and tribe Ricinodendreae. Vernicia and Givotia may be recognized based on wood anatomical and morphological characters. Th e tribes Micrandreae and Adenoclineae have considerable similarity in wood anatomy. Th e wood structure of the monogeneric tribes Trigonostemoneae and Geloneae idicate a close relationship with the tribe Crotoneae.Th e pantropical subfamily Crotonoideae is one of three subfamilies of the spurge family Euphorbiaceae s.s . Th e subfamily include notable economic products such as cassava ( Manihot esculenta ), rubber ( Hevea brasiliensis ) and tung oils ( Vernicia spp.), as well as many medicinal plants (Balakrishnan and Chakrabarty 2007).Crotonoideae is traditionally circumscribed to contain laticiferous taxa with crotonoid pollen. Morphology-based classifi cations for the subfamily have been proposed by M ü ller

Human-woodland interactions during the Pre-Aksumite and Aksumite periods in northeastern Tigray, Ethiopia: insights from the wood charcoal analyses from Mezber and Ona Adi

“…According to Metcalfe and Chalk (1950: 1223-1227, the Crotonoideae subfamily shows mostly moderately small (50-100 µm) to mediumsized (100-200 µm) vessels. A similar range (70-150 µm) is given by Jangid and Gupta (2016) for Indian species of Croton sp. Besides vessel lumina, both publications highlight the diagnostic potential of apotracheal parenchyma organization -both diffuse-in-aggregates and forming narrow bands up to three cells wide -and ray structureuniseriate and multiseriate rays present, heterocellular with several rows of upright and / or square marginal cells -to identify the woods of the Crotonoideae subfamily in general (Metcalfe and Chalk 1950;Jangid and Gupta 2016).…”

Wood anatomy of some members of Euphorbiaceae and Phyllanthaceae from Assam, India

“…Raturi et al (2001) mentioned gross features, few microscopic features and general properties of 26 genera of this family. The anatomy of wood specimens of sub families of family Euphorbiaceae available in FRI, Xylarium, Dehradun was performed to reflect their systematic, ecology and evolutionary aspects (Jangid & Gupta 2015, 2016Jangid et al 2017). However, there is limited report on wood anatomy of different genera available in Assam.…”