Microsorum pteropus 'Orange Narrow'

This pretty, vigorous form of the Java fern (Microsorum pteropus, more recently also known as Leptochilus pteropus) became widespread in the aquarium hobby in the 2010s, but is still a rarity. Nothing is known for certain about its exact origin, it was possibly found in southern Thailand. Initially passed on under M. pteropus "Orange", it was later named M. pteropus "Orange Narrow".
This Java fern has a similar leaf shape and grows only slightly larger than Microsorum pteropus 'Narrow', but shows an interesting colouration. The tips and midrib of the young, sprouting leaves are coloured brown-orange or brown-red, as with the much larger and broad-leaved M. pteropus 'Red'. However, the leaves of 'Orange Narrow' are narrow-lanceolate and usually around 15 - 25, maximum 30 cm long and 1.8 - 3 cm wide. Older leaves take on a medium green, relatively light colour. The leaves are comparatively smooth, not as heavily hammered as some other Java ferns. The leaves are usually simple (undivided), but old, vigorous plants can occasionally develop one or two narrow lobes at the base of the leaf blade.
A special feature of the Orange Java fern is that the relatively thin, long rhizomes tend to grow upright at an angle. This must be taken into account when using it as a perennial plant, as the rhizomes only partially creep horizontally on the substrate. However, excessively luxuriant upward growth can be counteracted by pruning the rhizomes.

Microsorum pteropus "Orange Narrow" does not differ from other Java fern varieties in terms of requirements. It is an easy plant that also grows in aquariums with low light and without additional CO₂. However, the Orange Java fern develops best with a complete supply of macro and micronutrients via the water column, the addition of CO₂ and at least moderate light intensity. A bright location promotes the reddish colouring of the young leaves. Like other Java ferns, M. pteropus 'Orange Narrow' can be attached to driftwood or rock as a perching plant. The fern can also be attached to the substrate, but the roots and rhizomes should not be buried, otherwise they could rot. As already mentioned, the rhizomes tend to grow upright at an angle. Pruning the rhizomes promotes their branching and thus a denser growth of the plant.
As is generally the case with Java ferns, "Orange Narrow" can also be propagated prolifically. You can divide the plant or cut the rhizome into several pieces with a few leaves. Young plants often develop on the underside of the leaves, especially on old and severed leaves.

Microsorum pteropus "Orange Narrow" is a rare form of Java fern with distinctive, bright brown-orange and fresh green colours. As a perching plant on wood or rock, the fern creates an interesting accent. With its moderate leaf size, it fits well in smaller tanks, but looks particularly impressive as a dense and lushly developed stand in large aquascapes.