. Morphology of gymnosperms. Gymnosperms; Plant morphology. CONIFERALES (TAXACEAE) 327 seeds (p. 43). All the other conifers have lost all traces of their nucellar vascular systems. In Saxegothaea (149, 150, 152) there is a remarkable extension of the tip of the nucellus, which protrudes beyond the micropyle into an irregular, flaring apex, which is said to become covered by a sticky secretion and to act as a stigma, continuing to grow for about two months after pollination (fig. 379). This character appears, in less degree, in Fig. 379.—Saxegothaea conspicua: longitudinal section
. Morphology of gymnosperms. Gymnosperms; Plant morphology. CONIFERALES (TAXACEAE) 327 seeds (p. 43). All the other conifers have lost all traces of their nucellar vascular systems. In Saxegothaea (149, 150, 152) there is a remarkable extension of the tip of the nucellus, which protrudes beyond the micropyle into an irregular, flaring apex, which is said to become covered by a sticky secretion and to act as a stigma, continuing to grow for about two months after pollination (fig. 379). This character appears, in less degree, in Fig. 379.—Saxegothaea conspicua: longitudinal section of ovule, showing the stigma-like extension of the nucellus; X50.—After Noeen (149). The development of the sporogenous tissue has been traced by Strasburger (100) in Taxus, and it is presumably the same in the other Taxaceae. The archesporium is a hypodermal plate, which divides periclinally as usual. The outer cells, in connection with the overlying epidermal cells, produce the large mass of sterile tissue that caps the nucellus. Each primary sporogenous cell (mother cell) is the innermost cell of a long row, and the number of mother cells is approximately the same as the number of archesporial cells (fig. 380). In most genera, apparently, these rows are not dis-. 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 Coulter, John Merle, 1851-1928; Chamberlain, Charles Joseph, b. 1863; Coulter, John Merle, 1851-1928. Morphology of spermatophytes. Part I. Gymnosperms. Chicago, University of Chicago Press
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