Notice the difference in the shield fronds
between the two
For years the Platycerium alcicorne and Platycerium vassei were thought to be two different species. Wendy Franks in her book Platycerium Fern Facts does not list the P. alcicorne as a unique species, but does list the P. vassei species. Currently most knowledgeable growers believe they are the same plant and today only P. alcicorne is used to classify this platy species. The most common P. alcicorne found is the African version pictured top left. It grows in East Africa. The platy with the deep rippled shield frond is from Madagascar and is more difficult to find in collections. Probably because it is more difficult to grow than the African one. The regions in which the African P. alcicorne grows suggests it is more cold tolerant than most Platycerium. but will not take much frost. Platycerium alcicorne is a fine choice for an easy Platycerium that can be grown out doors in bright light where front is extremely rare.
To some degree, the P. alcicorne is also similar to the P. ellisii, P. panama, P. ridleyi, and P. madagascariense in they all grow rounded shield fronds suggesting they are from rain forests with plenty of water and the shield frond protects the rhizome from rotting from excess watering.
For years Roy Vail has suspected the P. alcicorne could be found in
the Seychelles islands, which is in the Indian Ocean, east of
Madagascar and East Africa, but on one of his recent travels (2014),
he concluded there are no Platycerium in the Seychelles. He
found two cultivated in a garden, but one was a P. biforcatum and the
other a P. hillii, probably imported from Australia.
These photos taken from Roy Vail's web site show the Madagascar P. alcicorne. Also from Madagascar is the P. madagascarinese which has similar deep indentions on the shield frond but they are more like a waffle pattern where these are more like valleys. The P. ridleyi also has a similar shield frond. It is interesting but few photos on Google of the Platycerium alcicorne Madagascar form show these deep valleys
Roy reports that the P. alcicorne from Madagascar tends to be darker green with many hairs. Some individuals have fertile fronds that are dark green on the top, and nearly white with hairs on the underside.
There appears to be more differences between the African and
Madagascar platys. The African platy is yellow-green in color,
waxy with nearly no hairs. Their shield fronds turn rich brown
when they die.
The Madagascar plants tend to be dark green, with many hair. Some individuals have fertile fronds that are dark green on top, and nearly white with hairs in the underside. Theri shields become nearly black when dead. And the Madagascar plants develop folds in the upper half of the shields when given enough light.
I can't find much documentation in this but in photos, the African platy appears to have long slender fingers on the wide fertile fronds, where the Madagascar platy has two forms, One with wide fertile fronds and one form with harrow fertile fronds. This may be a result of the growing conditions.
Roy Vail reports that the Africa plants are somewhat less tolerant of excess water than the Madagascar plants. The Africa plants also pup more freely. Both types are slightly more sensitive to cold than P biforcatum.
Plant Glossary ]