Halimeda distorta (Yamada) Hillis-Col.

Scientific Description

Habit and structure. Thallus green to pale green (drying grey to cream), forming sprawling irregularly shaped decumbent clumps spreading laterally for some distance over firm substrata, attached at several points. Branching dichotomous or trichotomous, with successive segments mostly not aligned. Segments heavily calcified, reniform to subcircular, occasionally trilobed or with scalloped margins, 8–12 mm long and 9–15 mm wide, often prominently curved, with central and radiating ribs often conspicuous in dried material. Cortex with utricles in 2 or 3 layers; peripheral utricles obconical in side view, slightly constricted at the base, 30–50 μm diam. and polygonal in surface view, remaining laterally attached after decalcification. Secondary and tertiary utricles cylindrical and occasionally without constrictions, 25–36 μm diam. Medullary siphons 80–120 μm diam., fusing at nodes in groups of 3 or 4 for c. 110 μm.

Distribution. Tropical Indo-west Pacific.

Habitat. Usually growing on rock.

[After Huisman & Verbruggen, Algae of Australia: Mar. Benthic Algae of North-western Australia, 1. Green and Brown Algae 128 (2015)]