Batrachospermum gombakense Kumano et Ratnasabapathy (Batrachospermaceae, Rhodophyta) is reported for the first time from Sabah, Malaysia on the island of Borneo. This species was found attached to submerged rocks and boulders of clear stream waters of Sungai Tabin in the Tabin Wildlife Reserve, Lahad Datu. It is characterized by the following combination of features:(i) Plant dioecious, brownish dark purple, 1-3 cm high, 300-550 cm in diameter, more or less dichotomously branched, not very mucilaginous; (ii) Spermatangia spherical, in clusters on lateral short branchlets at the middle of fascicle or shortened branchlets; (iii )Carpogonium bearing branch arising from pericentral cell ,consisting of 1- 3 pentagonal cells; (iv) Trichogyne inversed conical or club-shaped, indistinctly stalked; and (v) Carposporophytes single, axial, spherical to ellipsoidal, and carposporangia ovoidal. Batrachospermum gombakense is distributed in both Peninsular Malaysia and Sabah, Malaysia in Borneo. This finding contributes to efforts in mapping the distribution of species of the genus Batrachospermum in the Indo-Malaysian North Australian phycogeographical region (IMNAR).
