Catkin

cat·kin (kăt’kĭn) A usually dense, cylindrical, often drooping cluster of unisexual apetalous flowers found in willows, birches, and oaks. Also called ament. Willow –...

Buttress

but·tress (bŭt’rĭs) Supported against strain in any direction by a conspicuous ridge-like enlargement of the trunk vertically to the roots. Several of these buttresses often give a tree a square...