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
Human uses of plants in genetic engineering led to developments in crops. Genetically modified crops introduce new traits to plants which they do not have naturally. These can bring benefits such as a decrease in the use of harmful pesticides, by building in qualities such as insect resistance and herbicide tolerance. The ability of trees to graft is occasionally exploited by tree shaping to create living root bridges in Meghalaya and Nagaland states in India and on the islands of Sumatra and Java in Indonesia. The aerial roots of rubber fig trees, "Ficus elastica", are used to form suspension bridges across mountain streams. Plants