What Is the Green Fern on a Fruit Tree?

Ferns

• The fern family, which consists of three living groups, the marattiales, ophioglossales and leptosporangiate, or epiphytic, ferns, once dominated plant life on Earth. Ferns date back 417 million years to the Devonian period. At this time, they ranged from tiny, moss-like species to towering tree ferns. Unlike most other plants alive today, ferns reproduce through spores rather than flowers and seeds. With the rise of flowering plants, ferns lost their traction and many species became extinct. Flowering plants, or angiosperms, comprise more than 96 percent of modern plant life. However, the leptosporangiate fern family still contains 2,282 epiphytic species.

Epiphytes

• Epiphytic ferns adapted to the spread of angiosperms by learning to live with -- and on -- them rather than competing with them. Unlike most other plants, epiphytic ferns live without soil. Rather, they obtain nutrients and moisture from rain, the air and tree leaves. Because most epiphytes grow naturally beneath tree canopies, most prefer light to partial shade and well drained planting materials that consist of shredded bark, sphagnum moss and tree fern fiber.

Platycerium

• Epiphytic ferns from the Platycerium genus, also known as staghorn ferns, grow naturally across the tropics but can thrive when introduced to cooler regions. The 17 species in this genus get their name from their antler-like foliage. Tiny white hairs cover these upright, green fronds, an adaptation that prevents moisture loss. In the wild, staghorn ferns can weigh up to a few hundred pounds, but ornamentally grown species are generally much smaller. The most common staghorn in the U.S., P. bifurcatum, tolerates low temperatures to 15 degrees F and is grown as an ornamental plant. Other staghorns that grow in fruit trees include P. veitchii, which has silvery fronds; P. andinum, which is covered with silver hairs and requires shade; P. elephantotis, which produces large, unbranched fronds; and P. superbum, which has long, reclining, light-green fronds.

Polypodium

• Several members of the Polypodium genus grow in fruit trees. These epiphytes include the licorice fern (P. glycyrrhiza), which prefers mossy, moist tree trunks and often grows on maple and alder trees. Licorice ferns have smooth, dark fronds. This cold-hardy fern grows on the western coast of North America, from Alaska to the Baja, as well as across Eurasia and southern Africa. The hoary fern (P. incanum), which grows in regions of the central and southeastern U.S., has short, thick fronds with mossy green tops and scaly, gray bottoms. In times of drought, the hoary ferns rolls up its fronds and goes into a dormant state until rain falls again.