Galaxaura rugosa (J. Ellis et Solander) J. V. Lamouroux, 1816

Division     Rhodophyta
Class     Florideophyceae
Order     Nemaliales
Family    Galaxauraceae
Basionym     Corallina rugosa Ellis & Solander
SynonymCorallina rugosa J.Ellis & Solander; Dichotomaria rugosa (Ellis & Solander) Lamarck; Dichotomaria rugosa (Ellis & Solander) Lamarck; Halysium rugosum (Ellis & Solander) Kützing; Corallina lapidescens Ellis & Solander; Corallina lichenoides Ellis & Solander; Galaxaura lapidescens (Ellis & Solander) Lamouroux; Galaxaura annulata Lamouroux; Dichotomaria lapidescens (Ellis & Solander) Lamarck; Galaxaura lichenoides (Ellis & Solander) Lamouroux; Digenea dichotoma Audouin; Dichotomaria lichenoides (Ellis & Solander) Blainville; Alysium lapidescens (Ellis & Solander) Kützing; Spongotrichum dichotomum Kützing

    Thallus lightly calcified, 4-11 cm high, composed of short, entirely terete, intertwined, irregularly alternately branched axes 1-3 mm in diameter, evenly covered with reddish brown filaments. Assimilatory filaments stiff, both short (2-3 cells long, to 500 μm, with ovoid to spherical terminal cells to 35 μm in diameter) and long (to 1.6 mm, subtended by globose basal cells). Pseudoparenchymatous cortical layers absent. Medullary filaments colourless and loose, separated by a ring of calcification from the more compact, pigmented assimilatory filaments. Tetrasporangia cruciately divided, terminal on long assimilatory filaments.


Lithophytic, grows on corals and sandy rocks.

Distribution in India

Lakshadweep, Andaman Islands, Tamil Nadu.