Glossary of Plant Systematics (1st ed.) by Simpson (2006)
- (a) At or near the top, tip, or end of a structure. (position) (b) Style arising at the apex of the ovary. (style position) (c) With the placenta at the top of the ovary. Syn: pendulous. (placentation)
Glossary of The Cell (5th ed.) by Alberts et al. (2008)
- Referring to the tip of a cell, a structure, or an organ. The apical surface of an epithelial cell is the exposed free surface, opposite to the basal surface. The basal surface rests on the basal lamina that separates the epithelium from other tissue.
- Simpson, M. G. 2006. Plant Systematics. -xi + 590 pp. Elsevier Academic Press, Oxford.
- Alberts, B., Johnson, A., Lewis, J. Raff, M., Roberts, K. & Walter P. 2008. Molecular Biology of the Cell, 5th ed. -xxxiv + 1616 pp. Garland Science, New York.