[1] The genus was originally classified under family Hypneaceae,[2] which was considered distinct from Cystoclonoiaceae on the basis of differences in their carposporophyte structure,[3][4] and the shape of the thalli and cortical cells.

[5] However, these criteria were questioned and molecular analysis later showed that the two families had similar vegetative and reproductive characters.

Newly generated DNA barcodes of the geographic isolates of this native carrageenophyte in this study is expected to be a key in tracing its further dispersal routes, either natural or deliberate.

Thallus color is highly variable, with yellow, green, pink, red, brown and black being observed.

Other countries with many endemic species of Hypnea include South Africa, Australia, Japan, Indonesia, Mauritius, the Philippines, India, and Brazil.

[13][9] Carrageenans are abundant in the cell walls of some red algae, where they provide the thallus with additional flexibility to protect it from the impacts of herbivory, wave action, and desiccation.

Hypnea is cultivated in many tropical countries such as the Philippines, Brazil, Bangladesh, India and Vietnam for food and for their kappa- carrageenan extracts.

[15] Most experimental cultivation activities have been done using Hypnea musciformis, and its highly variable morphology may be partly responsible for the inconsistency in the results of these experiments.