Eucheuma serra (J. Agardh) J. Agardh
Eucheuma serra is a species of Rhodophyta (red algae), with a dark red or yellowish white body, meaty and cartilaginous, in the shape of flat column at a diameter of 0.1-0.4 cm, featuring pinnate or irregular branches pointed on the tip with thorny stems lined pinnately on the edge looking like saw. The body is divided into back and belly, creeping upward obliquely, with many tubercles on the lower or bump-like appressoria. Branches are often interconnected, forming lumps as wide as 10-15 cm. The body is multiaxially structured inside, with the central pith comprising many small cells, transparent and round epidermic cells, and tiny surface cells containing chromatophore.
Eucheuma serra is widely found in the tepid oceans like the south of Japan, Ryuku Islands, Taiwan, mainland China, the Philippines, Indonesia, Malaysia and Sri Lanka. In Taiwan, it is distributed across the island and off-shore isles, mainly in the subtidal reefs within 10 meters deep, and in particular, likes to tuft in the protruding-cape oceans with strong currents. It can be seen all year round, flourishing between March and June. They especially grow massively in the southern entrance of Longdong and Audi into a surprising number, which are important economically-valued seaweed, edible for salad or stir-fry, medicinal for tumor or phlegm, resistant against insects and extractable for carrageenan.