The Crispy Wave Fern is a cultivar of the popular houseplant species Asplenium nidus. A beautifully bright green fern with characteristically sword-shaped, ruffled leaves give it the common name âCrispy Waveâ. Or it also goes by âBirdâs Nest Fernâ for the way the leaves radiate outward, leaving a leafy basin in the centre.Despite the fact that Asplenium nidus can grow fairly large, itâs actually an effective epiphyte. In its native South East Asian countries, youâll often find it naturally growing in the forked branches of trees. Fun fact, the Crispy Wave Plant was rated highly by NASA for its air purification qualities â making it a very useful terrarium plant indeed.