Grateloupia elliptica

Thallus foliaceous, cartilaginous, 20-30(-60) cm long, 5-15 cm broad, young plants entire, leaf-like, older incised into several blades, 3-8 cm width, mucilaginous, dark purple-red to brownish-red color. Blade with widely-cuneate base without stalk. Thallus smooth-edged, undulate. In transverse section, cortex composed of outer 5-10 rows of oval to elongated densely compacted cells, 4.5-6×6-13(-16) mm; inner cortex of larger cells loosely arranged, roundish to irregular shape, 13-16 mm across; medulla of loosely arranged cellular filaments intertwined with rhizoids and stellate cells. Tetrasporangia elongated, 18-20×50-72 μm, cruciately divided, imbedded in cortex, scattered over the thallus. Cystocarps subspherical, 320-400 μm diam., imbedded in outer medulla. Attachment by discoid holdfast. Growing on rocks, in the subtidal zone.

Countries of the Asia-Pacific Region.