Evolutionary history of plants and radially symmetrical, is an integumented megasporangium surrounded by a cupule. The megasporangium bears an unopened distal extension protruding above the multilobed integument. It is suspected that the extension was involved in anemophilous pollination. "Runcaria" sheds new light on the sequence of character acquisition leading to the seed. "Runcaria" has all of the qualities of seed plants except for a solid seed coat and a system to guide the pollen to the ovule. The first spermatophytes (literally: "seed plants") – that is, the first plants to bear true seeds – are called pteridosperms: literally, "seed ferns", so called because their
The Power of Movement in Plants The Power of Movement in Plants The Power of Movement in Plants is a book by Charles Darwin on phototropism and other types of movement in plants. This book continues his work in producing evidence for his theory of natural selection. As it was one of his last books, followed only by the publication of "The Formation of Vegetable Mould through the Action of Worms", he was assisted by his son Francis in conducting the necessary experiments and preparing the manuscript. The "Power of Movement in Plants" was published 6 November 1880, and 1500 copies were quickly sold by publisher