. A textbook of botany for colleges and universities ... Botany. 714 ECOLOGY Annuals and —The plants hitherto considered may be placed in three general classes: those with uniform seasonal aspect; those in which the leaves are shed at the inception of the period of drought or cold; and those in which all aerial portions are lost at the beginning of the inclement season. The fourth and final class of land plants is that in which the entire plant dies at the inception of the inclement season. The most representative members of this class are the annuals,. ~, >»-^«i^. S-0«J<-
. A textbook of botany for colleges and universities ... Botany. 714 ECOLOGY Annuals and —The plants hitherto considered may be placed in three general classes: those with uniform seasonal aspect; those in which the leaves are shed at the inception of the period of drought or cold; and those in which all aerial portions are lost at the beginning of the inclement season. The fourth and final class of land plants is that in which the entire plant dies at the inception of the inclement season. The most representative members of this class are the annuals,. ~, >»-^«i^. S-0«J<- Fig. 1036. — Winter rosettes of an evening primose (Oenothera), with leaves closely appressed to the ground; note the small amount of leaf overlap, due to high-ranked phyllotaxy and to variation in leaf length; Chicago, 111. — Photograph by Land. which are plants that live only in the favorable season, and which have fewer protective structures than do other plants. The annual alone among plants remains through seasons of severity solely in the form of its progeny, the seed. Related to the annuals are the biennials, which are plants that live in two vegetative seasons. In the first season most biennials develop a rosette (as in the evening primrose, peppergrass, and mullein, figs. 1036, 840), which remains as such through the period of drought or cold. During the second vegetative season an erect shoot commonly appears and develops flowers and fruits, death ensuing at the inception of the second inclement period. Annuals and biennials do not perennate, because they fail to develop lateral basal shoots; occasionally, however, some individuals of species. 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; Barnes, Charles Reid, 1858-1910, joint author; Cowles, Henry Chandl
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectbotany, bookyear1910
