Padina distromatica Hauck 1887


Division     Ochrophyta
Class     Phaeophyceae
Order     Dictyotales
Family    Dictyotaceae

    Thalli circular or flabelliform, yellowish to pale brown, 4-6 cm height. Thallus arising from a rhizoidal cushion, 6-15mm in diameter. Thallus stipitate, 0.8-1.7 cm height, blades slightly to deeply split into several fan-shaped to suborbicular blades, thin overlapping on the margins, margin entire; heavily calcified on the lower surface. Apex involute. Thallus composed of two cell layers throughout, 83–97 μm thick.


    Tetrasporangia present only on the upper surface of the thallus, fe rtile zone consists of 5 rows of concentrically placed, well developed or rudimentary hairs interspersed with 2 rows of sporangia. Sporangia not symmetrically disposed. Tetrasporangia stalked, 60-96 µm long and 58-110 µm broad. Antheridial sori found on both surfaces and formed discontinuous lines or patches without an indusium. Antheridia oblong to obovate, 80-140 µm long and 45- 85 µmin wide, each locule more or less squarish, 2-5 µm wide.


Ecology

Lithophytic


Distribution in India

Tamil Nadu, Andaman Islands