The principles of biology . l facts respecting the formsof clusters of flowers, apart from the forms of the flowers them-selves. Two kindred kinds of LeguminoscB will serve to showhow the members of clusters are distributed in an all-sided man-ner or in a two-sided manner, according as the circumstancesare alike on aU sides or alike on only two sides. In Hippd-crepis, represented in Fig. 226, the flowers growing at the end of a vertical stem, are arrangedround it iu radial in Melilotus, , where the axillary stembearing the flowers is soplaced in relation to the m^i
The principles of biology . l facts respecting the formsof clusters of flowers, apart from the forms of the flowers them-selves. Two kindred kinds of LeguminoscB will serve to showhow the members of clusters are distributed in an all-sided man-ner or in a two-sided manner, according as the circumstancesare alike on aU sides or alike on only two sides. In Hippd-crepis, represented in Fig. 226, the flowers growing at the end of a vertical stem, are arrangedround it iu radial in Melilotus, , where the axillary stembearing the flowers is soplaced in relation to the m^iastem, that its outer and innersides are difierently condi-tioned, the flowers are all onthe outer side : the cluster isbilaterally symmetrical, sinceit may be cut into approx-imately equal and similargroups by a vertical plane passing through the maia axis. Plants of this same tribe furnish clusters of intermediatecharacters having intermediate conditions. Among these,as among the clusters which other types present, may be. THE SHAPES OF FLOWERS. 147 found some in whicli conformity to the general law is notobvious. The discussion of these apparent anomalies wouldcarry us too much out of our course. A clue to the explana-tion of them wiU, I beKeve, be found in the explanationpresently to be given of certain kindred anomalies in theforms of individual flowers. § 233. The radially-symmetrical form is common to aUindividual flowers that have vertical axes. In plants whichare practically if not literally uniaxial, and bear their flowersat the ends of upright stalks, so that the faces open hori-zontally, the petals are disposed in an all-sided way. Cro-cuses, TuKps, and Poppies are fainiHar examples of this struc-ture occurring under these conditions. A Ranunculus 228, will serve as a typical one. Similarly, flowers^,g ^>i»r which have peduncles flexible enough tolet them hang directly downwards, andare not laterally iucommoded, are alsoradial; as in the Fuchsia, Pi
Size: 1432px × 1746px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, bookdecade1860, booksubjectbiology, bookyear1864
