Evolutionary history of plants foliage consisted of fern-like fronds, although they were not closely related to ferns. The oldest fossil evidence of seed plants is of Late Devonian age, and they appear to have evolved out of an earlier group known as the progymnosperms. These early seed plants ranged from trees to small, rambling shrubs; like most early progymnosperms, they were woody plants with fern-like foliage. They all bore ovules, but no cones, fruit or similar. While it is difficult to track the early evolution of seeds, the lineage of the seed ferns may be traced from the simple trimerophytes through homosporous Aneurophytes. This
The Power of Movement in Plants the work. The work was begun in earnest late in 1877, after his work on climbing plants (1875) and insectivorous plants (1875) stimulated his interest in the subject. At times, Darwin despaired of ever finishing the work, as the book outgrew his original expectations: As the book neared completion, he summarised its underlying viewpoint: The work concerns itself with how plants respond to external stimuli and examines these processes in individual plants to gain understanding of some general principles governing their growth and life. This continues Darwin’s work of elucidating how natural selection works and specifically how plants have adapted