Apex, the tip or point of the spire.
Apophysis, an excrescence.
Approximating, approaching near to, or near together.
Arcuated, bent in the form of an arch.
Arcuations, bendings, curvings.
Area, the surface contained between lines or boundaries.
Arenose, sandy.
Areola, a small area or circle.
Articulations, junctures, or joinings.
Ascititious, supplemental, additional.