Myanmar forests are rich in ferns, but we were surprised to see staghorn ferns as well.
Hawaii gardens have long been famous for their vast array of orchids and other showy flowering plants. Ferns, on the other hand, don’t get top billing in most landscapes even though they were probably the first vascular plants to make Hawaii their home.
In fact, ferns were around long before flowering plants evolved. It is estimated there are more than 12,000 species today. Most are relatively small, but some tree ferns in Myanmar reach 30 or more feet in height.
These tree ferns are remnants of the Carboniferous age and might have existed more than 100 million years ago, long before flowering plants. The majority of species are found in humid tropical and subtropical regions, but also are well-represented in temperate forests.
Ferns can be found growing on rocks, in caves or growing in the tops of trees wherever there is enough moisture and humidity. Ferns growing on other plants along with orchids and bromeliads are referred to as epiphytes.
We commonly see epiphytitic types growing on hapuu, tree branches and even rocky, soilless areas. In the past decade, other air plants such as bromeliads have become popular because of their colorful foliage and flowers.
Other additions to the list of epiphytes for the small gardens are the staghorn or elkhorn ferns. A few species of staghorn, or Platycerium, have been grown here for years but are by no means considered common.
Of course, the Platycerium should not be confused with the false staghorn, or uluhe, of Hawaii forests. This is actually a climbing fern, Dicaranopteris linearis, which can grow into almost impenetrable thickets in the lowland rain forests.
The true staghorn ferns grow epiphytically on support trees mainly in tropical areas of the world. Staghorns come from such places as the Pacific rim, which includes Australia, Papua New Guinea, the Philippines and the Malay Peninsula. Borneo, India, Africa, and Madagascar are also represented. One species, Platycerium andinum, comes from Peru and Bolivia. The main species found in the forests of Myanmar is Platycerium coranarium.
Although still plentiful in their native habitat, it has been only within the past 30 years that they have been grown by nurseries here, and some are still considered to be quite rare. Of the 18 species of staghorn ferns, the one most familiar to people is probably Platycerium bifurcatum, which is native to Australia. It has been reported that this species has yielded up to 50 cultivars, or hybrids.
The name “Platycerium” derives from a Greek word meaning broad horn. The word “platy” means broad and “keras” means horn, hence, “Platycerium.” This describes the shape of the lower, or fertile, fronds, which actually resemble a set of stag’s antlers.
All of the staghorn species are members of the fern family. An interesting theory related to the genus Platycerium is that it is considered somewhat of a missing link in the evolution of ferns.
When the fern spore germinates, it first develops a flat, shield-like structure called a gametophyte, or thalli. The fern we recognize develops from this shield-like structure and the thalli disappears. Because the Platycerium’s basal frond is virtually intact and plays an integral part in its growth habits, it is thought that this basal frond represents a transition between older and present-day forms.
A fossilized spore of Platycerium was identified in sandstone dating to the Cretaceous Period, which supports various theories that this plant family has been around for millions of years, including during the era of the dinosaurs. This denotes a heritage of great antiquity. Studies of the genus date back to the early 18th century, when these ferns were first identified in Africa.
Fossil images left in coal deposits 500 million years ago tell us that ferns were the first plants to evolve true leaves. Platyceriums have two distinct sets of leaves.
The basal leaves adhere by root structures to their support. The fertile fronds project outward from a central apex in the basal frond. These fertile fronds can form a dramatic drooping effect, as with the Platycerium bufurcatum and Platycerium coronarium species, or they can be erect as with Platycerium veitchii.
The fertile frond carries spores in splotches on the underside of the fronds and is a key in some species identification.
Platycerium grande is distinguished from a similar cousin, Platycerium superbum, by being smaller. It also has two distinct spore patches on the underside of its fertile fronds, while Platycerium superbum has one large patch.
As these fertile fronds grow and mature, they eventually yellow and fall off. The basal fronds play a different role in the plant’s overall function. As they mature, they turn brown and “thatch up” to form a thick matting. This helps protect the stems and roots of the plant and also serves as a “composting” center for the debris that falls into the cavity created by the buildup of fronds. This provides food for growth for this type of epiphytic fern.
Although these spectacular ferns occur most often in tropical areas, many will survive prolonged dry seasons and are quite hardy.
Many cultivars were developed, and there is much speculation about whether any of them have occurred naturally. The general theory among horticulturists is that they simply escaped from cultivation and established themselves.
This sounds especially feasible considering their antiquity and the interest these unusual plants have generated throughout the centuries.