The wood anatomy of Cornaceae, Alangiaceae, Garryaceae, and Nyssaceae constituting the Cornales in the sense of Cronquist (1981, 1988) is described in great detail and subjected to a cladistic analysis. A microscopic identification key to the woods studied is given. The alliance in eludes seventeen genera, mostly of trees and shrubs, very rarely herbs. Although wood anatomically fairly homogeneous, variation exists in both qualitative and quantitative characters. Some of the latter show distinct latitudinal trends within individual genera, and character states have only been recognised taking their latitudinal dependencies into account. The character states ultimately recognised in these continuously varying quantitative characters coincide with intergeneric or intersectional gaps. The cladistic analysis based on a datamatrix with twenty-one characters (Table 3) and using Cercidiphyllum, Daphniphyllum, and Hamamelis as outgroups yielded a strict consensus tree with a quadrichotomy with two monophyletic clades, Hydrangea paniculata (a representative of the closely allied Hydrangeaceae) and Daphniphyllum (Fig. 81). One weakly supported clade includes Alangium, Camptotheca, Cornus, Curtisia, Davidia, Diplopanax, Mastixia, and Nyssa without any robust lineages among them. The other genera, Aralidium, Aucuba, Corokia, Garrya, Griselinia, Helwingia, Melanophylla and Toricellia, constitute a second, well-supported clade. Two Hydrangea taxa included in the analysis nest in the second clade and a basal branching respectively. The wood anatomical diversity pattern thus supports a family concept of Cornaceae including Cornus, Curtisia, Diplopanax, Mastixia, Alangiaceae, and Nyssaceae, and exclusion of the genera in the other clade. There is remarkable agreement between some of these wood anatomical results and recent cladistic analyses of rbcL sequences by Xiang and co-workers. The infrageneric classification of Cornus, Alangium and Nyssa is also discussed.
