Boodlea composita
Chlorophyta, Siphonocladaceae
Authority: (Harvey) Brand
Hawaiian name: none
Characteristic feature: Rounded cushions made of a fine network of fine branching filaments.
Description: Plants low (2.5-4 cm) cushion, to 6(-8) cm across, spongy network of segmented erect filaments developing from branched prostrate segments; branching sparse on basal portions of axes, more abundant above; erect axes at first flattened and fanlike with branches initially opposite and regular, later irregular (alternate, secund, to radial); branches joined into three-dimensional mesh by small specialized cells that attach one filament to another; attachment can be apical or lateral on segments; anastomoses more numerous with age, forming final spongy network; primary axes 150-350 µm in diameter, branch segments 70-125 µm in diameter.
Habitat: On intertidal or shallow subtidal rocks or coral; frequent in multi-species turf associations.
Hawaiian distribution: All main Hawaiian Islands.
Other: Plants of Boodlea composita are darker green, more spongiose, and softer in texture than Microdictyon species; rarely flattened.