Trochodendrales

(botany) An order of dicotyledonous trees in the subclass Hamamelidae characterized by primitively vesselless wood and unique, elongate, often branched idioblasts in the leaves.

An order of flowering plants, division Magnoliophyta (Angiospermae), in the Eudicotyledon. The order consists of two families, the Trochodendraceae and Tetracentraceae, each with only a single species. The group is of considerable botanical and evolutionary interest, as it is situated near the base of the advanced Eudicotyledon and links this larger group with more primitive flowering plants. Trochodendrales comprise trees of eastern and southeastern Asia with primitive (without vessels) wood. The flowers have a much reduced perianth with scarcely sealed carpels that are only slightly fused to each other. See also Eudicotyledons; Magnoliophyta.

Trochodendrales is a botanical name for an order of flowering plants. An order by this name was recognised in the Cronquist system, as comprising the families Tetracentraceae and Trochodendraceae, each consisting of a single species. This order was placed in the subclass Hamamelidae [sic], in class Magnoliopsida [=dicotyledons].

The Dahlgren system made the same choice at the rank of family and order, but placed this order in superorder Rosanae in subclass Magnoliidae [=dicotyledons].

In the APG II system these two species are united into one family under the latter name (with the split into two families being optional), and the family is placed among the basal eudicots.

The AP-Website [accessed 9 May 2006] also accepts this order.

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