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.
Ferns and seed plants are similar in having two kinds of plants present in their reproductive life cycle, but overall ferns reproduce very differently than seed plants. The familiar fern plant, described in the preceding paragraph, is the sporophyte (spore-bearing phase). Fern fronds bear organs known as sporangia.