Anatomical study of secondary xylem in Malvales plants, including four families, five genera and ten species grown in Korea, was carried out to elucidate relationship among genera of families in the order.
Wood of Elaeocarpus is diffuse porous and shows angular vessels in radial multiples of 2-14 cells and a few apotracheal of paratracheal parenchyma. Tiliaceous genera have diffuse porous wood, vessels in solitary distribution and apotracheal parenchyma of sinuous scalariform uniseriate band. In the family, Tilia shows angular vessel, noded and tile-like cell in ray and storied tissue but Grewia has circular vessel. Hibiscus shows ring porous wood, circular solitary vessel and biseriate band of apotracheal and paratracheal parenchyma. Firmiana shows ring porous wood, circular solitaty vessel and confluent parenchyma. Many starch grains appear in ray and axial parenchyma.
Judging from arrangement, shape, length and diameter of vessel element and angle of end wall to vessel axis, and arrangement and shape of axial parenchyma, the lines of specialization in these genera are from primitive Elaeocarpaceae through less primitive Tiliaceae and less advanced Malvaceae to advanced Sterculiaceae.
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