Description:—The root-stock is creeping or ascending, several inches long, and nearly an inch thick. This thickness is made up, in considerable part, by the adherent bases of old stalks; the stalks being perfectly continuous with the root-stock, and so much crowded as to overlap each other. When fresh the root-stock is fleshy, and a longitudinal section of it shows that its substance passes so gradually into that of the stalk-bases, that no point of separation or distinction between the two can be selected. This kind of root-stock is found also in _Aspidium spinulosum_ and its allies, in _A. Filix-mas_, _A. cristatum_, _A. marginale_, _A. Nevadense_, _A. fragrans_, and _A. rigidum_, and in very many exotic species, and it is very unlike the root-stocks of _A. Thelypteris_, _A. Noveboracense_, and _A. unitum_, species which have been already described and figured in the present work. The parenchymatous portion of the root-stock is loaded with starch in very minute grains, as may be easily proved by adding a drop of alcoholic solution of iodine to a thin slice of the root-stock placed under a microscope, when the grains will be presently seen to turn blue, the recognized sign of starch. This abundance of nutritive material in the root-stock enables it to send up a fine circle of large fronds in the proper season of the year. The stalks are from nine to fifteen inches long, rather stout, green when living, but straw-color when dried for the herbarium, in which condition they are furrowed in front and along the two sides. At the base they are covered with large ovate-acuminate brown or sometimes dark and shining scales. Mixed in with these are smaller and narrower chaffy scales, which also are found along the whole length of the stalk and the rachis. The cross-section of the stalk shows two rather large roundish fibro-vascular bundles on the anterior side, and three, the middle one largest, at the back.