. The classification of flowering plants. Plants. HALORAGACEAE 303 containing intercellular spaces, and a central axis limited by a well-marked endodermis in which the few vascular elements are arranged in bundles isomerous with the leaf-traces. The short stout stem of Gunnera is polystelic, consisting of a parenchymatous ground-tissue through which run numerous vascular strands. The stem affords an interesting case of symbiosis from the fact that colonies of a s})ecies of Xostoc {N. Gunneme) penetrate and be- come enclosed within the outer lavers of the cortex. The flowers are inconspicuous,
. The classification of flowering plants. Plants. HALORAGACEAE 303 containing intercellular spaces, and a central axis limited by a well-marked endodermis in which the few vascular elements are arranged in bundles isomerous with the leaf-traces. The short stout stem of Gunnera is polystelic, consisting of a parenchymatous ground-tissue through which run numerous vascular strands. The stem affords an interesting case of symbiosis from the fact that colonies of a s})ecies of Xostoc {N. Gunneme) penetrate and be- come enclosed within the outer lavers of the cortex. The flowers are inconspicuous, with small free sepals; the petals when present are free and generally larger than the sepals, and have an imbricate. Fig. 195. A. Floral diagram of Haloragis erecta. B. Floral diagram of Gunnera petaloidea. C-F. Hippuris vulgaris. C. Flower, x 10. D. Fruit, x 15. E. Same cut lengthwise; s, remains of style; o, outer layer; i, hard inner layer of pericarp; t, testa surrounding the large embryo; p, plug in jDericarjD which becomes pushed out on germination, she^vn in F with portion of membranous testa attached. (A, B after Eichler.) or valvate aestivation: the stamens are free, with short filaments and normal anthers dehiscing longitudinally. Except in Gunnera the number of ovary-chambers corresponds with the number of the carpels; and there is a pendulous anatropous ovule, with two integuments, in each cell. In Haloragis and Myriophyllum the flowers are solitary or in dichasia in the leaf-axils, sometimes forming spikes, racemes or panicles by the reduction of the upper leaves to bracts. Each flower is subtended by a pair of bracteoles; in Gunnera they are ebracteate and crowded in large inflorescences, that of G. insignis from Costa Rica forming a pyramid 7 ft. high with a base 3 ft. broad. In Haloragis (fig. 195, A) the flower con- forms to the common Onagraceae tx^e, S4, P4, A4 — 4, G(4), the. Please note that these images are extracted from scanned page images that may ha
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Keywords: ., bookcentury1900, bookdecade1900, booksubjectplants, bookyear1904
