This widely distributed and mainly Palaeozoic genus is especially well represented in the coalfields of France where in some localities it contributed largely to the formation of seams of coal[544], and it is chiefly from the researches of French Palaeobotanists that our knowledge of its morphology is derived. _Cordaites_ has shared the fate of most other abundant fossil plants in the distribution of its _disjuncta membra_ among several genera and classes, but on the whole the information that is now available enables us to reconstruct the complete plant with a greater degree of confidence than is usually attainable. _Cordaites_ may be described as a forest-tree closely resembling in habit and probably in size the recent Conifer _Agathis_, more especially such species as _A. macrophyllus_, _A. vitiensis_ and others with leaves considerably longer than those of the Kauri Pine (_A. australis_)[545]. The main stem reached a considerable height before giving off scattered branches bearing spirally disposed, sessile, and often crowded leaves[546] like the foliage of _Agathis_. The absence of any evidence of a two-ranked arrangement of leaves on lateral branches suggests a general tendency towards a vertical rather than a horizontal direction of growth. The sessile and closely set leaves for the most part of leathery texture vary considerably in length and breadth in different types (figs. 466–472): in some the broadly linear lamina with its parallel veins and perfectly constructed I-shaped girders (fig. 465) reached a length of nearly 100 cm., in shape like the blade of a straight broad-sword or the leaves of a _Yucca_, torn by the wind into strips; in other forms the lamina is shorter and more obovate, while in some the leafy shoots must have looked like slender stems of the smaller-leaved Bamboos. There is no proof that young vegetative branches with their spirally rolled leaves[547] were protected by bud-scales, but some oval triangular scales (fig. 468, C), occasionally found in association with larger foliage-leaves, may have served that purpose. The branches from which leaves had recently fallen at the time of fossilisation are characterised by transversely elongated oval scars, occasionally showing a slightly curved row of pits like the marks of leaf-traces on the scars of a Horse Chestnut, sometimes terminating a feebly projecting decurrent leaf-cushion (fig. 466, C). The leaves persisted for a comparatively long period as in _Araucaria imbricata_, and on older leafless branches the scars are transversely stretched; the leaf-cushion loses its individuality and eventually the development of secondary cortical tissue causes the exfoliation of the superficial bark.