An annotated list of brown seaweeds (Phaeophyceae) from Nakadori Island (northern Goto Islands, Nagasaki, Japan) Belleza, Dominic Franco C. Tateishi, Hiroto Tanimae, Shin-Ichiro Kobayashi, Taishun Aota, Tomoyuki Urasawa, Toshiki Nishihara, Gregory N. Phytotaxa 2025 2025-03-18 694 1 1 24 (Mertens ex Turner) C. Agardh, 1820 C. Agardh 1820 Turner [136,840,229,256] Phaeophyceae Sargassaceae Sargassum Chromista Fucales 15 16 Ochrophyta species siliquastrum    Typelocality:— NagasakiHarbor, Nagasaki, Japan   Description and remarks:—The specimen has a robust discoid holdfast with two branches arising from it. The main axis is 2.5 mmwide and has three angles on its cross-section (i.e., triquetrous). The leaves are dense around the upper parts of the thallus and can reach lengths of up to 7 cm, with widths of about 2–3 mmand have serrate or dentate margins. The midribs are also distinct on the leaves. The vesicles are located on upper, secondary branches and are borne on stalks, 3–5 mmlong. The vesicles are avoid and may be observed with leaflets on their apices. This species is common in Yokoura in mid spring and has been found along the exposed and shallow rocky areas near the wave breaker.   Material examined:—18ECS1-3-2