This section is from the book "The Florists' Manual", by William Scott. Also available from Amazon: The Florist's Manual.
The spleenworts, as the asplenium genus has been termed (from the supposed medicinal value that ancient practitioners believed them to possess), form one of the largest fern groups in cultivation, over 300 species having been described, though it is rather doubtful if this whole number is at the present time in cultivation.
As may be expected in so large a genus, the aspleniums are very widely distributed, and in consequence we find among them species requiring warm house treatment, others that need comparatively little heat, and a few that are quite hardy in our northern and eastern states, there being more than half a dozen species that are native here.
The subject of our illustration, A. bulbiferum, belongs to the second division, or those that require only moderate heat, and though in commerce for many years, is by no means so plentiful as its merits would justify. A. bulbiferum is an evergreen fern from New Zealand, the home of many of our finest ferns, and has finely divided fronds of nearly triangular outline, these fronds reaching a length of nearly two feet in a good specimen, and being nearly one foot in breadth at the widest part. The plant has a gracefully drooping habit, this being accentuated by the weight of the numerous tiny young plants that frequently form on the upper side of the fronds.
This proliferous habit is found in several of the aspleniums, but is perhaps most marked in the species under consideration, the fronds often being studded over with young plants that are just showing their first leaf. This peculiarity is often taken advantage of in the propagation of A. bulbiferum, a common method being to bend over these proliferous fronds and then peg them down on the surface of a flat filled with light sandy soil, and the latter being kept moist soon induces the young plants to form roots, after which they may be readily detached from the parent frond. This operation is, of course, carried out in a shaded fern house, where the atmospheric conditions are favorable for the establishment of these young plants. The aspleniums in general produce spores quite freely, and A. bulbiferum is no exception to the rule, but as the spores are somewhat slow in germination, the process above described is probably more often used. No special treatment is called for in growing this fern, and young plants grow nicely in company with Adiantum cuneatum and Pteris serrulata, though possibly enjoying a little more shade than is absolutely necessary for those species.