This species is named for Nathaniel Wallich, Director of the Botanic Garden for 30 years, starting in 1815.
This species has tall spreading shields with many rounded lobes along their upper edge. It forms a definite basket. The shields may all be brown while the fertile fronds are stillgreen.
The fertile fronds have distinctively prominent veins on the upper side. Their shape varies greatly in cultivation. Although there is one main lobe which hangs down and has the main spore patch on it, there may be a lobe to its side with another spore patch, and other lobes to the side of that which have none. If there are enough lobes, the frond becomes fan-like and the outer lobes may even blend in with the shields. The area with the spore patch extends forward and may have points on the edge.
The distribution of P. wallichii in Burma, Thailand, and the Yunnan Province of China. The dotted line is the Tropic of Cancer.
In nature P. wallichii may In be about xml:namespace prefix = st1 />xml:namespace prefix = st1 />1.3 m. ( 4.5 ft. ) tall, butin cultivation it tends tobe smaller. Few who grow P. wallichii successfully. It may die from rots, but more often it goes into dormancy and never comes out. There is little agreement among those who grow P.wallichii successfully on how the species should be treated. One gives it no water while dormant, another keeps it watered well all year so it does not go dormant. More experiences are needed.
Importers report plants from India are smaller and more apt to go dormant than those from Thailand. Since in Thailand it grows together with P.holttumii plants from there should be adapted to the same conditions as P.holttumii monsoon forests with definite wet and dry seasons. Plants from India are collected from near the border of Burma and China, out of the tropics, where they grow on rocks as well as trees. It could be that cool temperatures during dormancy are important to those plants.
The future of this species probably depends more on sporelings being raised under cultivation here than on imports. These plants could be better conditioned to the environment in collections. The spore are green, an indication they do not live long. They germinate quickly. Sporelings, under very moist conditions.
Hennipman and Roos consider P.wallichii to be most closely related to P. elephantotis. Hoshizaki in an earlier study put it closer to the P.superbum group.
P.wallichii must be considered a difficult species, prone to rots and permanent dormancy. More experience with it is needed. It seems safest to obtain plants from Thailand or sporelings.