Thanks dwayne
Java fern is a true aquatic plant in the sense that it grows just fine submersed, unlike some of those plants they sell such as Arrowhead. While that plant may survive marginally, it will die and wither when underwater. This is not the case with java fern. Many, if not most, of the true aquatic plants also have the ability to grow in an emersed form. Glosso, dwarf hair grass, moneywort, hydrocotyle sp. and swords are all examples.
In my experience, my java fern has always wilted and died off where it grows above the water.
As for it being a normal growth pattern... I don't know about that. I've got about...450 java fern leaves and this is the first and only to display the trilobe pattern...
EDIT: The link I was going to give from the krib is down, but here are some quick tidbits:
"Java Fern is found on jungle floors where soft, acidic water sprays on its leaves..."
". Since Java Fern is often found near moving water in emersed form, it likes swift oxygenated water during the evening (hence, the leathery leaves). "
http://www.netpets.com/fish/reference/freshref/javafern2.html
I can't really vouch for the validity of that link though, I only scanned it briefly....
Ohh, here's a link I like...(time to clean the favorites folder perhaps LOL). I'll share it here simply because it's good reading, IMO [geek].
"Microsorum
The genus Microsorum includes some 60 species, some of which are known to be aquatic. The genus is found in Southeast Asia. Microsorum (mistakenly spelled as “Microsorium” in many older texts) has simple leaves, sometimes three, and rarely five lobes. Spores mature on emergent fronds and presumably are distributed by the wind.
In the wild, Microsorum grow in moist tropical areas, usually along the edge of streams. They are frequently found in the spray zone of waterfalls. Microsorum is more salt tolerant than many plants, and is often collected from brackish water areas. It presents a problem for aquarists when these wild collected plants are offered for sale. The leaves that have grown under brackish conditions often deteriorate under softer aquarium water conditions. The plant may recover if the rhizome is left in place, but the novice aquarist often gives up at this point and throws the “lifeless” rhizome away. It is usually better to purchase captive-propagated specimens. These plants are already acclimated to aquarium conditions and will not deteriorate the way wild ones can.
Currently, there is only one species, M. pteropus, that is widely cultivated on a commercial basis under the common name, Java fern. It is possible that at least one other species may find its way into the aquarist’s hands from time to time. There are at least five variants of Java fern available either commercially or from other hobbyists in the U.S.
Tall broad leaf — the broad leaves of this variety have wavy margins. It easily grows 18 inches tall under good conditions. Leaves are usually about 2 times the length of the petiole. Trilobate leaves are commonplace on mature plants of this variety. Leaf plantlets are produced, but it is not as prolific as some other varieties, although it is easily reproduced by rhizome division.
Tall narrow leaf — this variety is similar in height to the tall broad leafed variety, but the leaves are only about 1 1/4 inches in width. The margins are quite straight, and the veins are deeply grooved, giving the leaves a geometric mosaic look. It is also quite common to see trilobate leaves on this variety.
Short narrow leaf — this is a much smaller variety and the possibility exists that it is actually a different species. It is darker in color than the taller types and the leaves are no more than about 6 inches long, including a 2-inch petiole. The leaves of this variety are much more closely spaced along the rhizome than in the larger types. While trilobate leaves do occasionally develop on fully mature specimens, they are not as common as those on the larger varieties. The plant produces large numbers of leaf plantlets and can also be propagated by rhizome division.
’Tropica’ — this is a variety developed by Tropica in Denmark. It is extremely decorative, similar in growth to the tall broad leaf variety. The leaves develop long extensions along the margins giving them a look similar to dandelion leaves. This variety is registered and cannot be reproduced commercially without the permission of Tropica.
’Tropica’ produces leaf plantlets, like the other forms of Java Fern, but the plantlets do not reliably show the leaf extensions seen on the parent plant. The only way to assure the leaf extensions will be seen in a propagated specimen is to propagate by division of the rhizome.
’Windeløv’ — this variety was also developed by Tropica and is also a registered variety that cannot be reproduced commercially without the permission of Tropica. It is a small variety, and at first glance might not be recognized as a Microsorum at all. The leaves are thin and highly branched, giving them a staghorn appearance when viewed individually. The plant is short in stature, and the many branched leaves grow closely spaced along the rhizome. This causes the plant to develop a lacy, mounded aspect that can be used to great advantage as a foil for large leafed plants."
http://www.csd.net/~cgadd/aqua/ah_main/dec1998.html
