(Aphyllum asperum, Rough Aphyllum, of Artis.)
"The Lepidodendra (Scaly-trees) are a tribe of plants whose remains abound in the Coal formation, and rival in number and magnitude the Calamites and Sigillariæ previously described. The name is derived from the imbricated or scaly appearance of the surface, occasioned by the little angular scars left by the separation of the leaves. Some of these trees have been found almost entire, from their roots to the topmost branches. One specimen, forty feet high, and thirteen feet in diameter at the base, and divided towards the summit into fifteen or twenty branches, was discovered in the Jarrow coal-mine, near Newcastle.[22]
[22] Wonders of Geology, sixth edition, vol. ii. p. 722.
"The foliage of these trees consists of simple linear leaves, spirally arranged around the stem, and which appear to have been shed from the base of the tree with age. The markings produced by the attachment of the leaves are never obliterated, and the twigs and branches are generally found covered with foliage. The originals are supposed by M. Adolphe Brongniart, notwithstanding their gigantic size, to have been closely related to the Lycopodia, or Club-mosses."[23]
[23] Medals of Creation, p. 144.
Associated with the stems of Lepidodendra, and oftentimes imbedded in masses of their foliage, and in some instances attached to the extremities of the branches, are numerous oblong or cylindrical scaly cones, garnished with leaves: an imperfect specimen is figured in [Plate IX.] fig. 1, and the vertical section of another in [Plate III.] fig. 6. These cones have received the name of Lepidostrobi (Scaly-cones), and are the seed-vessels or fruits of the Lepidodendra.[24]
[24] See Medals of Creation, p. 147, and lign. 31, p. 149.
These fossils often form the nuclei of the ironstone nodules from Coalbrook Dale, and are invested with a pure white hydrate of alumina; the leaflets, or more properly bracteæ, are often replaced by galena, or sulphuret of lead, giving rise to specimens of great beauty and interest, as examples of the electro-chemical changes which these fruits of the carboniferous forests have undergone.
The fossils figured in this Plate, are portions of a stem eleven feet in length, from near Hoyland, Yorkshire. Fig. 1, is from the upper part, and shows the carbonized scales attached; fig. 2, represents part of the lower end, in which the scales are decorticated, from the adhesion of the bark to the surrounding shale.
A. Shows the cicatrix, with its transverse gland that connects the scale, in the upper part
of the trunk.