Hypnea charoides

Thallus bushy, caespitose, loosely intricate at the base, 5-15(-20) cm high, dark reddish color. Branches cylindrical, 1–2 mm diam., covered with numerous slender, spinose branchlets with broad base and acute apices. In transverse section, cortex consist of 1(-2) rows of small pigmented cells; medulla consist of 1-2 rows of large cells (to 190×140 μm) surrounding a small axial cell and 1–2 rows of smaller cells (~100 μm across) of outer medulla (decreasing towards cortex). Lenticular thickenings in cell walls of medullary cells absent or occasionally present. Tetrasporangia zonately divided, develop at basal or middle part of swollen branchlets. Cystocarps subspherical, sessile, ~600 μm diam., solitary or in groups of 2–3, develop on branchlets near apces. Attachment by discoid holdfast. Growing on rocks, stones in the low intertidal zones of protected coasts.

Subtropical and tropical waters of Indian and Pacific Oceans.