This includes many of the ferns that are most useful to the commercial florist. Though many ferns of this class are classed as tropical, there are only a few that will not thrive in a minimum temperature of 55 degrees.
A few of the most familiar are: Acrostichum aureum, Adiantum trape-ziforme, Asplenium caudatum, Blech-num Brasiliense, Davallia divaricata, Nephrodium macrophyllum, Nephrolepis davallioides, Nephrolepis exaltata, Poly-podium aureum, Pteris tremula, Wood-wardia orientalis, and hundreds of others, both genera and species. In that class are our large decorative plants of pteris, nephrolepis and polypodium.
As the larger growing ferns are mostly from the tropics, so the dwarf-er, more compact growing ones are natives of colder or more temperate zones. There are not many commercial ferns taken from this class and, except to the student of ferns, they are less familiar. A few examples are several forms of Adiantum cuneatum, Asplenium For-niosum, Asplenium flabellifolium, Cheil-anthes fragrans, several davallias and many other genera. Some of the tropical species of these smaller ferns make excellent material for our fern pans. A list of the most desirable for this purpose will be given later on.
As is obvious from the above description, these form one of the most ornamental classes, and in classifying no regard to size has been considered. All are acquainted with the exquisite tints of Adiantum Farleyense, the bluish tint of Polypodium aureum, the variegated Nephrodium (Lastrea) opaca, and the beautifully colored fronds of Pteris tricolor. Several of the selaginellas have a most beautiful bronze and metallic hue, and S. rubella has a golden form that is much valued. Many genera have species in this class, among them the adiantum, blechnum, davallia, doodia, nephrodium, pellaea, polypodium, pteris and selaginella.
Here the author of the "Book of Ferns" remarks that "If we consider the many crested, variegated, congested, truncate, depauperated, revolute, cornute, marginate and other forms found in many genera, we feel bound to acknowledge that there is little if any doubt that ferns are as much addicted to variation as any other members of the vegetable kingdom." We readily believe this, for in this city there lived an old Englishman, a shoemaker, we believe, who when emigrating had brought with him from the Cumberland hills his beloved ferns and had in cultivation alone fifty different forms or varieties of the very common British fern, Scolopendrium vulgare, the hart's tongue fern of every English roadside. Several of these forms the old gentleman claimed to have discovered and named, and we believed him. He found the public was not craving for distinct and odd forms of his scolopendriums, and being withal too honest for this country, returned to his native land.
Just here an innocent little story occurs to me in connection with these formidable names for so innocent a plant. A gentleman with a taste for hardy ferns was annoyed with tramps and beggars intruding on his grounds, so he set up a sign which read, "Beggars Beware! Polypodiums and Seolopendriums Set Here!" It was the simple truth and had the desired effect.
The author above quoted goes on to say: "The creation of new species, especially among ferns, is mostly the result of a slow process of evolution by which nature produces new types inheriting more or less of the parental characters. To these same variations or freaks of nature we are indebted for the majority of our decorative trees and shrubs, as also for a goodly number of flowering and foliage plants of an herbaceous nature." Just so; that is plain, truthful language, and had the author been writing on zoology he would most likely have said the same about the variations in the species of animals, and back of species genera have been evolved in the same way, but not with animals as freaks of nature or ornament to the individual, as by their development in some direction that best suited them to their environment, and which comes back exactly to that great truth, "the survival of the fittest."
Polypodium Subauriculatum in Hanging Basket.
The variegated ferns exist in a number of genera. Perhaps the most familiar to us is Pteris argyrea, a fine free growing fern. The variegated form of Adiantum cuneatum is only interesting to the specialist. Variegation is found among adiantums, aspidiums, aspleniums, nephrodiums, polypodiums, pteris, scolopendriums and others.
While variegation is found mostly among ferns belonging to the tropics, cristation, as this form is known, is largely confined to the European or cooler species. Cristation consists in the subdivision of the extremities of the frond, forming a tassel, sometimes grotesque and sometimes very ornamental. And sometimes the tips or outline of the whole frond are divided and multiplied. It has been noticed that when these forms or monstrosities occur they reproduce themselves by spores with little variation. The most familiar forms we know are the crested pteris, cretica and serrulata; Adiantum cuneatum has several forms, and the grand Nephrole-pis davallioides furcans. Among other genera that give us crested forms are aspidium, asplenium, davallia, gymno-gramme, polypodium, woodwardia, etc.
Although occurring in fewer genera, the gold and silver ferns embrace some of the most beautiful plants, and are easy of culture. They are all of exotic origin, but will thrive very well in a winter night temperature of 55 degrees. The very attractive golden and silvery gym-nogrammes owe their beauty to the under side of the frond, which is covered with a thick coating of powder, giving the plant a marvelously rich appearance.
In cheilanthes the silvery appearance is produced by scales or hairs evenly and thickly distributed over the under surface of the fronds, and in the noble Cyathea dealbata the under side of the fronds have the appearance of being painted. Of all this class, the gymno-grammes are the best known and most useful, and if I could grow only two of them it would be G. chrysophylla, a perfect cloth of gold, and G. chrysophylla Peruviana, with grand silvery fronds. Other handsome ferns of this class will be found among the cheilanthes, glei-chenia and nothochlaena.