Padina arborescens Holmes, 1896

Belleza, Dominic Franco C., Tateishi, Hiroto, Tanimae, Shin-Ichiro, Kobayashi, Taishun, Aota, Tomoyuki, Urasawa, Toshiki & Nishihara, Gregory N., 2025, An annotated list of brown seaweeds (Phaeophyceae) from Nakadori Island (northern Goto Islands, Nagasaki, Japan), Phytotaxa 694 (1), pp. 1-24 : 10

Padina arborescens Holmes, 1896

Japanese name: ƯミƯチワ (umiuchiwa)

Type locality: —Enoshima, Kanagawa, Japan

Description and remarks: —Plants are prostrate with thalli 5–10 cm in length and 6–11 cm in width. Algae are attached to the rocky substrate via a rhizomatous holdfast. Blades are fan-shaped to reniform with occasional clefts while calcification is very light or absent. Fresh specimens are light brown but turn dark brown once dried.

This species is common among the rocky subtidal throughout all the study sites starting from early spring to mid-late summer. They grow densely on any hard substrate together with Colpomenia sinuosa and almost cover the entire stretch of rocks in the shallow areas. In the mid to later parts of summer, most specimens have torn blades and heavy damage due to herbivory.

Materials examined: —18ECS1-34 (1 to 23)