Fucus caespitosus Stackhouse, 1797 [1795–1801]: 59–60, pl. XII, nom. illeg. (syntype localities: various in Cornwall, England).
Fucus opuntia Goodenough & Woodward var. caespitosus Turner, 1802a: 387.
Gelidium corneum (Hudson) Lamouroux var. caespitosum (Turner) J. Agardh, 1851 [1851–1863]: 470.—Sonder, 1879: 83.— Lawson, 1980: 46.
INDIAN OCEAN DISTRIBUTION: Tanzania (Zanzibar).
Note: Fucus caespitosus Stackhouse, the intended basionym of Gelidium corneum var. caespitosum, is not priorable since it is a later homonym of F. caespitosus Forsskål (1775: 190; type locality: Mokha, Yemen), a name of uncertain application. Fucus opuntia var. caespitosus Turner is treated as a nomen novum in accordance with Art. 58.3.