. Class-book of botany : being outlines of the structure, physiology and classification of plants : with a flora of the United States and Canada. Botany; Botany; Botany. 106 THE PISTILS, OR GTNCECIUM. 520. The placenta are usually prominent lines or ridges extending along the ventral suture within the cell of the ovary, and bearing the ovules. They arc developed at each of the two edges of the carpellary leaf, and are consequently closely parallel when those edges are united, forming one double placenta in the cell of each ovary. 521. The simple carpel, with all its parts, is completely exempl
. Class-book of botany : being outlines of the structure, physiology and classification of plants : with a flora of the United States and Canada. Botany; Botany; Botany. 106 THE PISTILS, OR GTNCECIUM. 520. The placenta are usually prominent lines or ridges extending along the ventral suture within the cell of the ovary, and bearing the ovules. They arc developed at each of the two edges of the carpellary leaf, and are consequently closely parallel when those edges are united, forming one double placenta in the cell of each ovary. 521. The simple carpel, with all its parts, is completely exemplified in the pea- pod. When this is laid open at the ventral suture, the leaf form becomes manifest, with the peas (ovules) arranged in an alternate order along each margin, so as to form but one row when the pod is closed. In the pod of columbine the ovules form two distinct rows; in the simple plum carpel each margin bears a single ovule, and in the ono-ovuied cherry only one of the margins is fruitful. 522. The stigma is the glandular orifice of the ovary, communicat- ing with it either directly or through the tubiform style. It is usually globular and terminal, often linear and lateral, but subject to great va- riations in form. It is sometimes double or halved, or 2-lobed, even when belonging to a single carpel or to a simple style, as in Linden, where these carpels are surmounted by three pairs of stigmas. 523. The compound pistil consists of the united circle of pistils, just as the monopetalous corolla consists of the united circle of petals. The union occurs in every degree, always commencing at the base of the ovary and proceeding upward. Thus in columbine we see the car- pels (pistils) quite distinct; in early saxifrage cohering just at base; in pink as far as the top of the ovaries, with styles distinct; in evening primrose to the top of the styles, with stigmas distinct; and in Rhodo- dendron the union is complete throughout. 3ST 888 3S9 890 891 392 893. 88T, Ovary
Size: 2437px × 1025px
Photo credit: © The Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, bookdecade1860, booksubjectbotany, bookyear1861
