Ferns and Fungi

Abstract

It will perhaps come as a surprise to fern lovers to learn that these interesting and often delicate plants are as much subject to attack by parasitic fungi as are the higher plants. The fungi occur not only as parasites, but as symbiotic forms in the roots, as epiphytes on fronds and stems, and in a wide and bewildering variety as saprophytes or scavengers on all parts of dead and dying plants. Even the prothallia of ferns are attacked and destroyed by a number of the lower fungi. Seymour in his standard Host of the Fungi of North America lists approximately 200 species of fungi as growing on nearly 100 fern species-an array of enemies to make the stoutest fern quail! Pteridium, the common Bracken, for example, is host to some 30 fungi, a number of them distinctly parasitic. A forthcoming supplement to the Index will increase this record substantially. The interrelationship, as alternate rust hosts, which exists between the wheat crop and the barberry and between our white pines and currant bushes to their mutual disadvantage has been thoroughly publicized. It is not so well known, though unfortunately only too true, that a considerable number of North American ferns and our fir forests are involved in a similar rust fungus complex. There are three such rust genera, concerned, all abundantly represented in this country: Uredinopsis, Milesia,