. The botany of crop plants; a text and reference book. Botany, Economic. GRAMINE^ (pOACEiE), GRASS FAMILY 83 The grass fruit is called a grain or caryopsis. There is an abundance of starchy endosperm. Sometimes the grain is closely adherent to the palet and lemma, as in most barleys and oats. Phylogeny of Grasses.—The history of the evolution of a group of organ- isms is phylogeny. What is the origin of the grasses? Are they primitive forms, the progenitors of such closely related groups as the lilies and other common monocotyledonous plants; or are they a reduced group? By those who hold the
. The botany of crop plants; a text and reference book. Botany, Economic. GRAMINE^ (pOACEiE), GRASS FAMILY 83 The grass fruit is called a grain or caryopsis. There is an abundance of starchy endosperm. Sometimes the grain is closely adherent to the palet and lemma, as in most barleys and oats. Phylogeny of Grasses.—The history of the evolution of a group of organ- isms is phylogeny. What is the origin of the grasses? Are they primitive forms, the progenitors of such closely related groups as the lilies and other common monocotyledonous plants; or are they a reduced group? By those who hold the latter view, which is more widely accepted, grasses are con- sidered to have come from Hly-Hke plants by a reduction and modification of a number of part's of the flower. Examination of the floral diagram of a typical Hly flower is shown in Fig. 31. It has two sets of floral segments (which together constitute the perianth) which alternate, two whorls of stamens, three in each whorl, and a pistil divided into three chambers, hence tri-carpellary. The stamens of one whorl alternate with those in the other; those of the outer whorl alternate with the inner segments of the perianth. The three carpels alternate with the inner stamens. In Fig. 31 is shown the floral diagram of a grass flower with the rudimentary or missing parts shaded. According to the view that grasses are reduced Hhes; there was a reduction in the lobes of. Fig. 31.—Diagram of A lily flower, and B grass flower showing homologous structures. A, f, bract; ax, axis; op, outer perianth; ip, inner perianth; s, sta- mens; c, tricarpellary ovary. B, shaded struc- tures are aborted; le, lemma (bract); ax, axis; p and p', palet (outer perianth); I and I', lodicules (inner peri- anth); 5 and s', two whorls of stamens; c, tricarpellary ovary. {B after Schuster.). Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of thes
Size: 1007px × 2481px
Photo credit: © Library Book Collection / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., booka, bookcentury1900, bookdecade1910, booksubjectbotanyeconomic
