. Carnegie Institution of Washington publication. THE YOUNG SPOROPHYTK 69 Botrychium virginianum, the lamina, which although very greatly reduced never- theless is present, is bent over sharply against the stout petiole, which is strongly convex on its adaxial side. In the specimen figured there was no trace of a stipular sheath developed in the cotyledon, but sometimes this is very well developed, although the upper part of the cotyledon remains quite rudimentary. The little cotyledon has the rudimentary lamina distinctly ternate in outline and very much resembles some of the rudimentary earl
. Carnegie Institution of Washington publication. THE YOUNG SPOROPHYTK 69 Botrychium virginianum, the lamina, which although very greatly reduced never- theless is present, is bent over sharply against the stout petiole, which is strongly convex on its adaxial side. In the specimen figured there was no trace of a stipular sheath developed in the cotyledon, but sometimes this is very well developed, although the upper part of the cotyledon remains quite rudimentary. The little cotyledon has the rudimentary lamina distinctly ternate in outline and very much resembles some of the rudimentary early leaves found in Botrychium lunaria, as figured by Bruchmann. A single vascular bundle extends through the petiole of the cotyledon, nearly to the base of the lamina, but except in the basal region the development of the xylem is m;;ch reduced and is entirely lacking before the lamina is reached. The bundle of the cotyledon, where it bends at the base into the inter- node, is nearly as well developed as the bundle of the second internode which separates from the former just below the insertion of the cotyledon. On the opposite side of the second internode from the cotyledon, and extending downward through the first internode for a short distance below the level of the cotyledon, there is seen c6t. l'h,. 46. A, B. Two longitudinal sections of a young sporophyte of Helminthostaehys; pr, gametophyte. X6. C. Upper part of same, more enlarged; b, terminal bud; cot, cotyledon; /, lacuna in first internode. D. Apical region. /J, third leaf; sc, epidermal scales. X140. E. Tracheids showing bordered pits and thickened bars. X320. in the specimen figured a large lacuna, separated from the outside of the internode by about halt a dozen layers of cells and on its inner side from the endodermis of the stele by two or three layers of cells. This lacuna, as Lang pointed out, is not always present. At the upper end of the second internode can be seen the base of the second leaf, the stipular
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Keywords: ., bookauthorcarnegie, bookcentury1900, bookdecade1910, bookyear1911
