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
Kingdom of Plants 3D Kingdom of Plants 3D Kingdom of Plants 3D is a natural history documentary series written and presented by David Attenborough, which explores the world of plants. It was filmed over the course of a year at the Royal Botanical Gardens, Kew. The series premiered on 26 May 2012 on the Sky 3D network in the UK, with a 2D simulcast on Sky Atlantic HD. An IMAX cinema release is also planned. Each of the three episodes explores a different aspect of plant life. "Life in the Wet Zone" explains how plants first colonised wet and humid environments, "Solving the Secrets"