Lithophyllum longense (Corallinales, Rhodophyta): a species with a widespread Indian Ocean distribution

Lithophyllum longense is characterized from Long Reef, Western Australia, Australia and from Chwaka Bay, Zanzibar Island, Tanzania. Both plastid markers psbA and rbcL confirm that L. longense is a distinct species despite its being morpho-anatomically nearly indistinguishable from several other fruticose Lithophyllum species, differing in only one (from L. atlanticum, L. platyphyllum, L. sublicatum, L. yemenense) or two (from L. affine, L. incrustans, L. kotschyanum, L. neocongestum, L. kaiseri, L. pseudoplatyphyllum, L. subreduncum) character states. This is only the second tropical Lithophyllum species and the fourth tropical species confirmed by DNA sequencing to be widely distributed in the Indo-West Pacific.