Yes, the bottom part of the heads has me puzzled as well. There is one important piece of evidence to add here, the root head in the small-plants section.
Note the very long point at the bottom. This head makes it more obvious that the point is a continuation of the root shape rather than a part of the head shape itself. The tapering end looks like root rather than mnemonic.
Note the very long point at the bottom. This head makes it more obvious that the point is a continuation of the root shape rather than a part of the head shape itself. The tapering end looks like root rather than mnemonic.