. Morphology of gymnosperms. Gymnosperms; Plant morphology. CORDAITALES 173 of cells, and the dehiscence is longitudinal. The stalk is traversed by a single vascular strand which sends a branch to the base of each sporangium. There is no evidence that the stamens arise from the axils of bracts, but the two structures seem to replace each other; in fact, the stamen stalk is very little modified from the bract form. In Cordaianthus Saportanus the stamens are fewer in number, being restricted to the apical region of the strobilus, and the stalks are shorter. It is evident that this strobilus is t
. Morphology of gymnosperms. Gymnosperms; Plant morphology. CORDAITALES 173 of cells, and the dehiscence is longitudinal. The stalk is traversed by a single vascular strand which sends a branch to the base of each sporangium. There is no evidence that the stamens arise from the axils of bracts, but the two structures seem to replace each other; in fact, the stamen stalk is very little modified from the bract form. In Cordaianthus Saportanus the stamens are fewer in number, being restricted to the apical region of the strobilus, and the stalks are shorter. It is evident that this strobilus is to be interpreted as a mixture of sterile and fertile microsporophylls. If the sterile sporophylls were suppressed, the general con- dition of the staminate stro- bilus of Ginkgo would be attained, but the sporangia of that form are borne differently. This interpreta- tion implies that the stami- nate strobilus of Cordaitales is a simple one, and that the stamen stalk is a filament. The suggestion that each stamen is a "flower," and that therefore the stamen stalk is a branch (pedicel), is an attempt to interpret this strobilus by the staminate strobilus of Gnetales or by certain types of angiosperm inflorescence, an attempt which singularly disregards the sequence of evolution. The terminal and erect microsporangia of Cordaitales were. Fig. 205.—Cordaianthus Penjonii: longi- tudinal section of staminate strobilus, .showing microsporangia borne on long stalks; through- out the sporangium region, but especially below it, are numerous sterile bracts; Xio.—After Renatjit (3).. 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 C
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