. Fossil plants : for students of botany and geology . Paleobotany. 462 COENOPTERIDEAE [CH. climbing habit of A. scandens and possibly A. Grayi. The radial extension of the xylem and the consequent alternation of the yielding parenchymatous cortex and the more rigid tracheal arms would probably render the water-conducting elements less liable to injury in a twisting axis^. In Anachoropteris De- caisnii", described by Renault, and more especially in Astero- chlaena laxa^ Stenzel, a Lower Permian type from Saxony (fig. 324), the xylem of the stele is much more deeply lobed than in Ankyropte
. Fossil plants : for students of botany and geology . Paleobotany. 462 COENOPTERIDEAE [CH. climbing habit of A. scandens and possibly A. Grayi. The radial extension of the xylem and the consequent alternation of the yielding parenchymatous cortex and the more rigid tracheal arms would probably render the water-conducting elements less liable to injury in a twisting axis^. In Anachoropteris De- caisnii", described by Renault, and more especially in Astero- chlaena laxa^ Stenzel, a Lower Permian type from Saxony (fig. 324), the xylem of the stele is much more deeply lobed than in Ankyropteris Grayi or A. Fig. 318. Etapteris Scotti, P. Bert. (From Tansley, after Eenault.) Etapteris Scotti. Figs. 308, B; 309, E; 318. P. Bertrand has proposed this name for a species of petiole from the Lower Coal-Measures of England referred by Binney* to Zygopteris Lacattii Ren., and included by Williamson^ in his comprehensive genus Rachiopteris. Bertrand^ regards the English species, which is recorded also from Germany', as distinct from Renault's type^ and therefore proposes a new name. The petiole stele has the H-form, but its structure is simpler than that of the Ankyropteris petiole. The horizontal band of xylem has at each end two oval groups of tracheae connected with it by a single row of xylem 1 Compare figures of the vascular cylinders of climbing Dicotyledons given by Schenck (93). 2 For a figure of the stele see Tansley (08) p. 25, fig. 20. =* Stenzel (89) Pis. in. and iv. â > Binney (72). e Williamson (74) A. « Bertrand, P. (09) â > Felix (86) A. s Renault (69).. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Seward, A. C. (Albert Charles), 1863-1941. Cambridge : University Press
Size: 1658px × 1507px
Photo credit: © The Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, bookdecade1890, bookpublishercambr, bookyear1898
