Halimeda borneensis W.R.Taylor

Scientific Description

Habit and structure. Thallus erect, pale green (dried), the exposed part to 8–9 cm tall, growing from a bulbous holdfast c. 2.5 cm long and 1.5 cm wide. Axes dichotomous to trichotomous, not markedly rotated between successive segments. Basal segments cylindrical to compressed, bearing several distal axes. Segments flattened, variously shaped, irregular to trilobed, mostly 5–7 (–11) mm wide, 4–8 mm long and 0.75–1.00 mm thick, lacking a noticeable midrib. Medullary siphons 25–80 μm diam. Cortex of 3 or 4 utricle layers; peripheral utricles 30–55 μm diam. at the surface, mostly hexagonal in surface view, basally constricted; secondary and tertiary utricles of similar diameter to peripheral utricles but more elongate. Medullary siphons uniting into a horizontal plate at the nodes, with prominent pores 20–25 µm diam., these with thickened margins.

Distribution. Indo-west Pacific.

Habitat. Grows in unconsolidated substrata in the intertidal or shallow subtidal.

[After Huisman & Verbruggen, Algae of Australia: Mar. Benthic Algae of North-western Australia, 1. Green and Brown Algae 126 (2015)]