Nature and development of plants . avity formed in the peculiarity is one of the important characteristics of theangiosperms, as the name indicates. The megasporophyll, oftentermed the pistil or carpel, is usually a rather elongated, flask-shaped organ with a hollow swollen base and consists of astigma, style and ovary (Fig. 261B, 1) within which are pro-duced the megasporangia or ovules. Such a structure wouldresult if the edges of the leaf-like megasporophylls of previousgroups were inrolled so as to form a closed organ. The mega- 348 PRIMITIVE FLOWERS spores originate in the
Nature and development of plants . avity formed in the peculiarity is one of the important characteristics of theangiosperms, as the name indicates. The megasporophyll, oftentermed the pistil or carpel, is usually a rather elongated, flask-shaped organ with a hollow swollen base and consists of astigma, style and ovary (Fig. 261B, 1) within which are pro-duced the megasporangia or ovules. Such a structure wouldresult if the edges of the leaf-like megasporophylls of previousgroups were inrolled so as to form a closed organ. The mega- 348 PRIMITIVE FLOWERS spores originate in these sporangia as already noted in the gymno-sperms and usually but one megaspore is developed in eachsporangium (Fig. 261B, 2). 124. Development of the Flower of Angiosperms.—The sporo-phylls are variously associated in groups that are commonlycalled flowers. In its simplest form, the flower may be definedas a minute branch or receptacle bearing one or more sporo-phylls. Such a type is illustrated in the cat-tail (Fig. 262, B, C).
Size: 1000px × 2498px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1900, bookpublisher, booksubjectplants
