Wood Anatomy of Sabiaceae (S.L.)
Quantitative and qualitative data were offered for 30 taxa of Meliosma and one species each of Ophiocaryon and Sabia; qualitative data were available for additional species of Meliosma and Sabia. For a small family restricted to mesic sites, Sabiaceae had a wide range of wood anatomical expressions (e.g., long scalariform to simple perforation plates; heterocellular to homocellular multiseriate rays; tracheids, fiber-tracheids, or libriform fibers as imperforate tracheary elements; presence or absence of silica bodies and calcium oxalate crystals in rays). Growth ring type, vessel diameter, vessel density, and vessel element length were sensitively related to ecology, but to degree of winter cold rather than to aridity. Ophiocaryon differed somewhat from all or most species of Meliosma in quantitative features, but the genera agreed in qualitative features. Some authors segregate these arborescent or arboreal genera in Meliosmaceae because of distinctive features of Sabia, a liana genus; wood of lianas differs in anatomy from that of trees, and these features account for the wood differences between Sabia and Meliosma. All wood features of Sabiaceae are widespread in the genera of Rutales (Sapindales), even scalariform perforation plates. Sabiaceae are therefore best placed in Rutales, although wood of Sabiaceae is modally more primitive than that of other Rutales. Characters restricted to particular species were cited, but designation of them as diagnostic criteria was not advocated because the sampling of the family was rather incomplete.