Eucheuma arnoldii

Thallus having a coral-like appearance, bushy, coarse, cartilaginous, 5–17 cm high, dark purple to yellowish-purple. Branches cylindrical, with diameters 3–5 mm in small branches and more than 1 cm in large branches, densely covered with simple or compound spinose branchlets arranged in whorls on all sides. Branching is dense upright, irregularly dichotomous. In cross section, cortex composed of 1–2 rows of elongate outer cells, 10–15 mm long and 3–4 rows of oval to polygonal cells of inner cortex; medulla composed of small rhizoidal cells interspersed with large cells. Cystocarps prominent with ostiolate pericarp developing in spines. Growing on sandy bottom with stones and pebbles, dead coral fragments, in sheltered to moderately exposed areas, in lower intertidal to subtidal (to 10 m deep).

Africa, Asia (China, Taiwan, Japan), South-East Asia (Vietnam, Malaysia, Singapore, Philippines, Indonesia), Australia and New Zealand.