Represented only by the Genus
P. occidenta'lis, L. (American Plane-tree or Sycamore.) A fine large tree found in south-western. Ontario. Leaves alternate, rather scurfy when young, palmately-lobed or angled, the lobes sharp-pointed: stipules sheathing. Flowers monoecious, both sterile and fertile ones in catkin-like heads, without calyx or corolla, but with small scales intermixed. Ovaries in the fertile flowers club-shaped, tipped with the thread-like simple style, and downy at the base. Fertile heads solitary, on slender peduncles. The white bark separates into thin plates.