Oceaniopteris gibba

Oceaniopteris gibba, the miniature tree fern (syn. Blechnum gibbum), is a tropical species of fern in the family Blechnaceae, native to Fiji. It has received the Royal Horticultural Society's Award of Garden Merit. 
It grows to . With a vertical "trunk" (actually a rhizome), it has bright green fronds. As it does not tolerate temperatures below , in temperate zones it must be cultivated under glass all year round. It is a suitable subject for a greenhouse or conservatory. It requires an acid soil and a partially shaded position. 