These conditions of orchid-growing have undergone great changes of late years, and the plants are grown much as other stove and greenhouse plants in ordinary pots with composts not only of peat but of leaf-mould, and fibres from osmunda and polypodium ferns.
For potting or basketing purposes, or for plants requiring blockculture, the materials used are light fibrous peat, special leaf-mould, osmunda or polypodium fibre and living sphagnum moss, which supply free drainage for the copious supply of water required.
The two genera of this group, Osmunda and Todea, have thick erect stems, covered with the closely crowded leaf bases.
In Osmunda the region of the leaf which bears the sporangia has its lamina little developed; the leaf thus bears sterile and fertile pinnae, or, as in 0.
In habit some species of Alethopteris resembled the recent Angiopteris, while the Neuropteris foliage may be compared with that of an Osmunda.
The Paleocene deposits of Great Britain are of marine origin, and only yield pinecones and fragments of Osmunda.