. Our native ferns and their allies : with synoptical descriptions of the American Pteridophyta north of Mexico. Ferns. And Their Allies 41 positive knowledge of these intimately related species, and has made their identification a matter of comparatively easy investi- gation. The buds may be found enclosed in the base of the com- mon stalk (except in B. Virginianum where they are placed in an upright cavity at one side) and may be examined with a strong lens. The three divisions are summed up as follows: " I. Vernation wholly straight. B. simplex, Hitch. (Fig. 41). II. Vernation partly i
. Our native ferns and their allies : with synoptical descriptions of the American Pteridophyta north of Mexico. Ferns. And Their Allies 41 positive knowledge of these intimately related species, and has made their identification a matter of comparatively easy investi- gation. The buds may be found enclosed in the base of the com- mon stalk (except in B. Virginianum where they are placed in an upright cavity at one side) and may be examined with a strong lens. The three divisions are summed up as follows: " I. Vernation wholly straight. B. simplex, Hitch. (Fig. 41). II. Vernation partly inclined in one or both portions. B. lu- naria, Swz., (Fig. 42), B. boreale, Milde, B. matricaricefolium^ A. Br., (Fig. 43), and B. ternatum, Swz. (Fig. 44). III. Vernation wholly inclined, in the fertile frond recurved. B. lanceolatum, Angs., (Fig. 45), and B, Virginianum, 'SiV^z.^'' The special characters of each species will be found under the descriptions of the Botrychia later in this work. The cuts will be valuable for reference, and will enable even beginners to identify the species of this complicated genus with comparatively little difficulty. 93. Fructification.—In this order of plants the fructification consists of sporangia which unlike those of the true-ferns are not reticu- lated, possess no trace of a ring, open by a transverse slit, and are variously spiked and panicled. (Fig. 30). In the adder-tongues (Ophioglossum) the sporangia are large and cohere in two ranks along the margins of a single spike, opening transversely to discharge their copious sulphur-yellow spores. In the grape-ferns {Botrychium) the sporangia are globular and arranged in double rows along the narrow segments, more or less in panicles. Fig. 30. Enlarged In both genera the sporangia are not de- sporangia of Botry- veloped from the epidermal cells, but arise ;^^"! 'f;^""*' ^^'• r . ^ ^ , . . c (Onginal.) from a transformation of the mterior tissue 01 the leaf. This with othe
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