Foliose ↔ Spires
This grouping is one of the most variable; the terms used all describe thin plate colonies growing into a range of intricate and often delicate forms.
The plates may form tiers, whorls or vases (e.g. p.18 of the Coral Finder), which are stacked in a complex, multi-layered arrangement. Where plates are near-vertical they may be described as leafy or lettuce-like (e.g. Pavona, p. 20 of the Coral Finder), or where the plates are narrow, as flutes and spires (e.g. Pectinia, p. 20 of the Coral Finder).