Sargassum alternato-pinnatum Yamada, 1942

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 : 13

* Sargassum alternato-pinnatum Yamada, 1942

Japanese name: キレバモク (kirebamoku)

Type locality: —Hiuga, Miyazaki Prefecture, Japan (see Yamada, 1942)

Description and remarks: —This species is distinct for having warty growths on the main axis and branches. The leaves are narrow and elongated, about 2–5 cm long with serrate to dentate margins with scattered cryptostomata. The leaf apices may be lanceolate or forked while leaflets may bifurcate from the leaf margins. The vesicles are round and found on stalks, along the secondary or tertiary branches. This species is common in Aokata, Naname and Yokoura in the spring until mid summer months.

Materials examined: —18ECS1-124 (1 to 2) and 18ECS1-131 (1 to 10)