. Studies in fossil botany . Paleobotany. SPHENOPHYLLEAE 109 of considerable size (Fig. 46, A), from which the two sporangia hung down side by side, towards the axis of the It appears that the pedicels in this species were short, and that they were arranged in three concentric verticils, on each whorl of bracts—another apparent difference from Sphenophyllum Dawsoni. The pedicel, which much resembles a sterile bract in structure,. Fig. 45.—Bowmanites Romeri. Part of transverse section of cone, br, bracts ; pcd pedicel of sporangiophore ; sm, the two sporangia belonging to it. At a the la
. Studies in fossil botany . Paleobotany. SPHENOPHYLLEAE 109 of considerable size (Fig. 46, A), from which the two sporangia hung down side by side, towards the axis of the It appears that the pedicels in this species were short, and that they were arranged in three concentric verticils, on each whorl of bracts—another apparent difference from Sphenophyllum Dawsoni. The pedicel, which much resembles a sterile bract in structure,. Fig. 45.—Bowmanites Romeri. Part of transverse section of cone, br, bracts ; pcd pedicel of sporangiophore ; sm, the two sporangia belonging to it. At a the lamina of a sporangiophore is shown. X 10. After Solms-Laubach. is traversed by a vascular bundle, which, where it enters the scale at the top, divides into two branches to supply the two sporangia (Fig. 46, A). The anatomical struc- ture of the sporangiophore, allowing for the greater size and complication associated with the presence of two sporangia instead of one, closely resembles that of Sphenophyllum Dawsoni (Fig. 46). The sporangium has a wall several cells in thickness ; in 5. Dawsoni this is 1 In the transverse section (Fig. 45) the pairs of sporangia {sm) are shown, with the pedicel {pcd) between the two sporangia, and on their outer 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 Scott, Dukinfield Henry, 1854-1934. London, A. and C. Black
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