. A Manual of botany : being an introduction to the study of the structure, physiology, and classification of plants . Botany. 732 FOSSIL PLANTS OF THE CAEBONIFEROUS SYSTEM. to the rachis, sometimes confluent, a strong primary vein reaching the apex, the secondary veins being nearly straight, simple, or forked, rarely pinnate, sori rounded at the end of the secondary veins (fig. 909). In Neuropteris {mu^ov, a nerve) the frond is pinnate or bi- pinnate, pinnse sub-cordate at the base, distinct from the rachis, strong primary vein vanishing towards the apex, secondary veins oblique, arched, repe
. A Manual of botany : being an introduction to the study of the structure, physiology, and classification of plants . Botany. 732 FOSSIL PLANTS OF THE CAEBONIFEROUS SYSTEM. to the rachis, sometimes confluent, a strong primary vein reaching the apex, the secondary veins being nearly straight, simple, or forked, rarely pinnate, sori rounded at the end of the secondary veins (fig. 909). In Neuropteris {mu^ov, a nerve) the frond is pinnate or bi- pinnate, pinnse sub-cordate at the base, distinct from the rachis, strong primary vein vanishing towards the apex, secondary veins oblique, arched, repeatedly diohotomous (fig. 910). Lonchopteris has its frond multi-pinnatifid, and the leaflets more or less united together at Ithe base; midrib is distinct, and the veins are reticulated. Cyclopteris has simple orbicular leaves, undivided or lobed at the margin, the veins radiating from the base, with no midrib. Schizo- pteris resembles the last, but the frond is deeply divided into numerous unequal segments, which are usually lobed and taper-pointed. Oaulo- pteris and Psaronius are names given to the stems of Tree-ferns found in the coal-fields. Tree-ferns appear to have existed in Britain during the deposit of the coal strata, and to have occupied an important place in the flora. The stems of these ferns are included under the genus Caulopteris. The fronds have not been found attached; but it is probable that some of the fronds found in the Coal-measures have been connected with these stems. Prof W. C. Williamson says that the number of fossil ferns has been needlessly multiplied, and he includes the entire series of four petioles and stems found in the Coal- measures under the name Rachiopteris. These petioles belong, no doubt, to the difierent forms of fronds already described, such as. 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
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Keywords: ., bookcentury1800, bookdecade1870, booksubjectbotany, bookyear1875
