Corynocarpaceae group closely with Coriariaceae and Cucurbitaceae by axial
parenchyma types (vasicentric scanty plus apotracheal banded plus ray-adjac
ent, all in strands of 1-2 cells) and Homogeneous Type II rays. Begoniaceae
, Datiscaceae s. s., and Tetramelaceae group on the basis of absence of ban
ded axial parenchyma and subdivision of the vasicentric parenchyma into str
ands of 3-5 cells. All of the families of Cucurbitales (except Anisophyllea
ceae) have two unusual features: minimal borders on perforation plates and
unusually wide multiseriate rays (not accompanied by uniseriate rays). All
of the families except Anisophylleaceae have another unusual feature, stori
ed fusiform cambial initials. Anisophylleaceae have several wood features m
ore primitive than those of other Cucurbitales (tracheids, aliform axial pa
renchyma, nonstoried cambial initials), but the family is not necessarily e
xcluded from Cucurbitales. Data on wood of Colynocarpaceae are derived from
samples of three species of Corynocarpus; possible specific characters are
offered.