The Tropical Garden, Fall 2018

By Jennifer Possley

Rare native ferns mix with tropical ferns in this secluded spot in the Garden’s Rainforest

Our tropical Garden dazzles visitors with stately palms from around the world, layers of epiphytes, and colorful showy blooms. Yet sometimes the plant life in quieter, tucked-away areas can be just as alluring. The Isabel J. Foster Fern Glade is one such botanical treasure. Nestled within Fairchild’s Richard H. Simons Rainforest, this planting bed showcases the variety of shapes, textures and patterns in tropical ferns from around the world.

The roughly two-dozen fern species in the Fern Glade congregate around a handsome chunk of Miami’s natural oolitic limestone. Embedded within the stone is a tile bearing a 1980 dedication to Ms. Isabel J. Foster.

Foster, who passed away in 1976 at the age of 92, was the mother of Nell Foster Jennings, who was married to the Garden’s founder, Col. Robert Montgomery.

The Foster Fern Glade received a revamping this spring, thanks to the efforts of Fairchild’s new conservation horticulturist, Brian Harding, and his team of volunteers. Rare ferns of South Florida (collected by the author) now mix with tropical ferns from the extensive collections of Dr. Chad Husby, the Garden’s botanical horticulturist. The next time you visit the Garden, sneak away to this secluded spot in our Rainforest to revel in the wonders of ferns! For now, you can get a sneak peek at our ferns in these photos.

Microgramma heterophylla

The climbing vine fern grows only in the West Indies and extreme South Florida (Miami, Key Largo, the Everglades and Big Cypress National Preserve), where it is listed as an endangered species. This is one of several fern species for which Fairchild’s Conservation Team has conducted reintroduction projects, and it has been the most successfully introduced fern species thus far—93% of the 56 individuals we planted in 2014 and 2016 are alive, and many have climbed trees and begun to produce spores.

Microsorum punctatum (left) and M. musifolium

These two ferns in the genus Microsorum were donated to Husby by Charles Alford Plants, a Vero Beach nursery specializing in ferns. The fern on the left that appears to be fluorescing in a shaft of sunlight is Microsorum punctatum; M. musifolium, on the right, is also known as the “crocodile fern” for its scaly, lizard-like leaves.

Asplenium nidus

The Foster Fern Glade’s biggest fern (by far) is the bird’s nest fern. Easily 5 feet across, the strap-shaped leaves of this beautiful fern converge to form a large “nest.” The bird’s nest fern is native to Old World tropics as well as Hawaii.

Asplenium nidus ‘Supreme cobra’

In contrast with the natural, smooth-frond form of the bird’s nest fern is a cultivar of A. nidus with the demure name “Supreme Cobra.” Husby obtained this fascinating specimen during a 2015 trip to Thailand.

Ctenitis sloanei

The foliage shown here is from the endangered Florida tree fern. While it is not a true tree fern, mature members of this species have a tree-like form, including a “trunk” crowned by incredibly soft orange fur that protects the developing young fronds. Florida tree fern is often available for sale at Fairchild’s plant sales and it is a very popular choice.

Pteris argyraea

The silver brake fern is native to Southeast Asia, but its beautiful variegated fronds have led to it being cultivated around the world as an ornamental plant. This specimen actually comes directly from Southeast Asia—Thailand, to be exact, where Husby obtained it during a 2017 collecting trip.

Thelypteris sclerophylla

The stiff star-hair fern is named for the tiny, spiny, star-shaped hairs that coat the front and back sides of the fronds. Though they are invisible to the naked eye, these hairs give the plant a sandpapery feel. The stiff star-hair fern is found only in the Greater Antilles and in two of Miami-Dade County’s Environmentally Endangered Lands preserves, where it is extremely rare. Fairchild’s native plants conservation program maintains an ex situ conservation collection of this species.

Adiantum tenerum

The brittle maidenhair fern is common throughout the New World tropics, and is one of the more common ferns growing throughout Fairchild’s 83 acres. Its distribution in greater Florida is, however, very limited, so it is considered an endangered species. Ferns in the genus Adiantum bear their sporangia (where spores are formed) under the edges of curled-under leaf margins; this flap of tissue is called a “false indusium.”

Angiopteris sp.

This fern in the genus Angiopteris was collected by Husby from Hawaii’s Wahiawa Botanical Garden in 2013. We very much hope the fern is happy in the Foster Fern Glade, because (like all ferns in the family Marattiaceae), if it sporulates, it will do so by producing synangia—structures made out of multiple sporangia fused together, which look like tiny, oblong lotus pods.

Pteris bahamensis

The Bahama ladder brake is found only in Cuba, The Bahamas and Florida’s five southernmost counties, where it is listed as a threatened species. This species is unusual in that it tolerates a wide range of light levels. In shade, its fronds may reach three feet long and take on a deep green color. In full sun, plants are more yellow-green, with small, compact fronds. It is known to hybridize with a ubiquitous, non-native species called Chinese ladder brake (Pteris vittata).

Blechnum gibbum

The dwarf tree fern is native to the South Pacific islands of Fiji, Vanuatu and New Caledonia. Despite its relatively narrow global range, it is a popular choice for tropical and subtropical fern gardens, and is widely available for sale. The plant’s form is reminiscent of a sago palm (which is not a palm, but the cycad Cycas revoluta, but that’s another story).

Dennstaedtia bipinnata

The bipinnate cuplet fern gets its name from the cup-like, spore-bearing structures (involucres) that form along the edges of its fertile fronds. This species is found throughout the New World Tropics, and was once considered native to Palm Beach County, but that population is believed to have been extirpated. This particular plant was donated to Fairchild by Richard Moyroud, a longtime nurseryman in Lake Worth, Florida.