. The classification of flowering plants. Plants. CACTACEAE 309 which are produced on the shoot, was unable to compare the spines with leaves, and regarded them as emergences. In Opuntia, in addition to the spines, slender barbed bristles (glochidia) are formed on the inner side of the apex of the axillary shoot, which are homologous with the spines. Tig. 197. Opuntia Tuna. A. Segment of stem bearing a flower-bud, oi^en flower and yomig fruit, x ^. B. Areole shewing the spines embedded in wool and the glochidia, g, slightly enlarged. C. Upper part of a glochidium, enlarged. D. Flower in longit
. The classification of flowering plants. Plants. CACTACEAE 309 which are produced on the shoot, was unable to compare the spines with leaves, and regarded them as emergences. In Opuntia, in addition to the spines, slender barbed bristles (glochidia) are formed on the inner side of the apex of the axillary shoot, which are homologous with the spines. Tig. 197. Opuntia Tuna. A. Segment of stem bearing a flower-bud, oi^en flower and yomig fruit, x ^. B. Areole shewing the spines embedded in wool and the glochidia, g, slightly enlarged. C. Upper part of a glochidium, enlarged. D. Flower in longitudinal section, slightly enlarged. E. Fruit in longitudinal section shewing the seeds embedded in pulp, slightly re- duced. F. Seed, x 3. G. Seed in longitudinal section she^vdng the curved embryo. (fig. 197, C). In the section Cylindropuntiae each spine is commonly covered with a thin sheath, formed by the union of a layer of hairs. In some cases the spines are w^eakor even hair- like (Pilocereus), and in species of Mamillaria the epidermis develops hairs so that the spine becomes feather-like. In others, as in Leiichtenbergia, they are flat and papery. In. 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 Rendle, A. B. (Alfred Barton), 1865-1938. Cambridge, University press
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Keywords: ., bookcentury1900, bookdecade1900, booksubjectplants, bookyear1904
