. The elements of botany for beginners and for schools. Botany. SECTION 9.] ANTHERS. 101. Tetradi/namous, when, being only six, four of them surpass the other two, as in the Mustard-flower and all the Cruciferous family, Yig. 235. 286. The Filament is a kind of stalk to the anther, commonly slender or thread-like: it is to the anther nearly what the petiole is to the blade of a leaf. Therefore it is not an essential part. As a leaf may be without a stalk, so the anther may be Sessile, or without a filament. 287. The Anther is the essential part of the stamen. It is a sort of case, filled with
. The elements of botany for beginners and for schools. Botany. SECTION 9.] ANTHERS. 101. Tetradi/namous, when, being only six, four of them surpass the other two, as in the Mustard-flower and all the Cruciferous family, Yig. 235. 286. The Filament is a kind of stalk to the anther, commonly slender or thread-like: it is to the anther nearly what the petiole is to the blade of a leaf. Therefore it is not an essential part. As a leaf may be without a stalk, so the anther may be Sessile, or without a filament. 287. The Anther is the essential part of the stamen. It is a sort of case, filled with a line powder, the Pollen, which serves to fertilize the pis- til, so that it may perfect seeds. The anther is said to be IiDiate (as in Fig. 292), when it is attached by its base to the very apex of the filament, turning neither inward nor outward ; Adnate (as in Fig. 293), when attached as it were by one face, usually for its whole length, to the side of a continuation of the filament; and Versatile (as in Fig. 29 f), when fixed by or near its middle only to the very point of the filament, so as to swing loosely, as in the Lily, in Grasses, etc. Versatile or ad- nate anthers are Introrse, or Incumbent, when facing in- ward, that is, toward the centre of the flow- er, as in Magnolia, Water-Lily, etc. Extrorse, when facing outwardly, as in the Tulip-tree. 288. Rarely does a stamen bear any resemblance to a leaf, or even to a petal or flower-leaf. Nevertheless, the botanist's idea of a stamen is that it answers to a leaf developed in a peculiar form and for a special purpose. In the filament he sees the stalk of the leaf; iu the anther, the blade. Tiie blade of a leaf consists of two similar sides; so the anther consists of two Lobes or Cells, one answering to the left, the other to the right, side of the blade. The two lobes are often connected by a prolongation of the filament, which answers to the midrib of a leaf; this is called the Connective. This is conspicuous in Fig. 29
Size: 1544px × 1618px
Photo credit: © Paul Fearn / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookpublishernewyorkamericanboo, booksubjectbotany, bookyear1887
