桑

Bottom tree radical - the indexing component. Anchors 桑 firmly as a kind of tree. The whole character is a compound pictograph: a leafy crown above (叒) on a tree trunk below (木), specifically the mulberry - the tree whose leaves feed silkworms, central to traditional Chinese sericulture. Hence the Sang surname and the 沧桑 'vicissitudes' image.

Top 叒 - a cluster of three 又-like elements, here picturing the dense crown of leaves and small fruits at the top of a mulberry tree. The triple shape evokes a thick canopy where silkworm farmers gather leaves. 叒 is rare standalone but appears as the upper element here and in 桒 (variant of 桑).