. Botany for high schools. Botany. HORNED LIVERWORTS the stem. The plant clings very closely to the bark of the tree which aids in retaining moisture. In addition each of these leaves has a lobe on the under side (next the tree) which is sac-like and holds water. This water is doled out to the plant during dry periods. It remains so long in these pockets that minute animals belonging to the crustacean group make it their home. In Cali- fornia one of the livenvorts growing on the ground forms subterranean tubers which tide the plant over the dry season. 479. The capsule (sporogonium) of the lea
. Botany for high schools. Botany. HORNED LIVERWORTS the stem. The plant clings very closely to the bark of the tree which aids in retaining moisture. In addition each of these leaves has a lobe on the under side (next the tree) which is sac-like and holds water. This water is doled out to the plant during dry periods. It remains so long in these pockets that minute animals belonging to the crustacean group make it their home. In Cali- fornia one of the livenvorts growing on the ground forms subterranean tubers which tide the plant over the dry season. 479. The capsule (sporogonium) of the leafy- stemmed liverwort.—This is a stalked capsule, and the capsule splits down to the base into four valves. In some species elaters are mixed wuth the spores. Fig. 291. HORNED LIVERWORTS (ANTHOCEROTES). pianroV""a foliose liver- 480. The horned liverworts.—The horned liver- Leafy part IS t he worts may be represented by Anthoceros. It grows in ftTiT^ldU' wet, muddy places. The thallus is thin, dark green, gp^r^pian?^ and irregularly branched and overlapping (fig. 292). The sexual organs are immersed in the thallus, the sperm casei in groups in a cavity, while the wall of the immersed egg case is united with adjacent cells of the thallus. The capsule is long, slender and slightly curved, its form suggesting the name of horned livenvorts. Its base is surrounded by a slender, short outgrowth of the thallus. The growing point of the capsule is near the base, the older portions being con- stantly raised by growth at the base. The capsule consists of a wall and a column of sterile tissue, between which is a layer of spore-bearing tissue in the form of a tube. Some of the cells of this spore-bearing tissue are mother cells of spores, each mother cell forming four spores. Other cells alternating with them form short, spirally marked elaters. From the nature of its grow^th the spores at the apex are older than those below. The capsule at maturity splits longitudinally and
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectbotany, bookyear1910
