Corallum a large crowded cluster of proliferous stems and branches. Branchlets and corallites wide spreading under surface of stem not flattened and can be recognized only by fewer and lower corallites. Branches and branchlets gradually tapering into cylindrical axial corallites, arcuate presumably because specimen is a peripheral stem. Radial corallites distant. Dimensions: stem 11 mm across; a branch 10 cm long, 9.5 mm across at middle.

Axial corallite cylindrical with rounded apex, 3-4 mm across, around 3.5 m exsert. Calice small, about 0.8 m, round. Wall thick, dense, non-costate, covered with very fine, low spinules with blunt tips. Septa in 2 cycles narrow, thin, smooth. Primaries short of radius midpoints, directives not distinguishable or very slightly so; secondaries very low ridges against wall, usually incomplete cycle.

Radial corallites vertical to surface of branches, somewhat seriate at apical regions. Two types: (1) tall tubulars, 4-5 mm high, 2 mm across, becoming gradually lower and smaller towards apex of branchlets, then still lower and wart-like towards the bases of stems and branches; calice oblique (few are vertical), slightly oval; wall moderately thick, closely costulate, echinulate; most of those just below axial are bent slightly outward; (2) small, low, thin walled corallites interspersed among tall ones; calice round, vertical; diameter around 1 mm, height at most 1 mm. In addition to the 2 types, taller corallites with small buds are found conspicuously.

Septa in tall radials 1 cycle only, directives quite distinguishable, the others very low ridges on calicinal wall. In lower corallite, septa less developed, sometimes even directives distinguishable.

Intercalicinal areas in upper portion show high porosity, spines not arranged as neatly as those on calicinal wall. Lower down, these areas become dense and spines have appearance and arrangement similar to those on calicinal wall.

Remarks: This species resembles A. formosa in the position of the corallites but they are much taller, stouter and more dispersed in the former.

Source:Nemenzo F (1971) Systematic studies on Philippine shallow water scleractinians: VII. Additional forms. Nat. Appli. Sci. Bull. 23:141-209.p pls.