The sections of the light spectrum which the âredâ and âgreenâ cones perceive overlap and this is why red and green colour vision deficiencies are often known as red/green colour blindness and why people with red and green deficiencies see the world in a similar way.
Wood fern (Dryopteris) Plant these delicate, medium-sized ferns in mixed borders to show off their feathery fronds. Autumn ferns (D. erythrosora) are one of the few ferns with seasonal color variation and their fronds change from pale gold and pink in spring to green in summer and rusty copper in fall. The ferns spread by underground stems to form swaths in garden beds.
Most ferns have what are called fiddleheads that expand into fronds, which are each delicately divided. Leptosporangiate ferns (sometimes called true ferns) are by far the largest group, but ferns as defined here (ferns sensu lato) include horsetails, whisk ferns, marattioid ferns, and ophioglossoid ferns.he gametophytes of ferns, however, are very different from those of seed plants. Instead, they resemble liverworts. A fern gametophyte typically consists of: 1  Prothallus: A green, photosynthetic structure that is one cell thick, usually heart or kidney shaped, 3â10 mm long and 2â8 mm broad.