Cryptocoryne spp.
A very large and diverse group (at least50 species, perhaps many more) of boor submerged plants from Southeast Asia. They are very variable in color and form, even within a particular species, and are therefore difficult to identify with any certainty.
In general, Cryptocoryne have Elon-gated, tough leaves, coloured mid-green to deep olive. Many are red- or purple-tinged, especially on the under-sides of the leaves. They grow, depend-in on species, from 7cm to 60cm (21/4-24in), and some grow best when part-submerged. Cryptocoryne grow best immoderate light or in shade, and usually thrive in soft acid water. They grow only slowly, so are expensive to buy, and do best if rooted in a mixture of peat and gravel. They reproduce in the aquarium by means of small plants produced on shoots running beneath the gravel, and will form dense clumps if left to their own devices. Their capacity for producing oxygen and removing nitrates is comparatively low, due to their slow growth rate. Most, and particularly the expensive large-leafed types, have the habit of drop-ping their leaves on being transplanted or even when the water is changed. Usually, these leaves are reground quite quickly, once a good root system has-been established.
The following species are most often available:
- C. affine (C. haerteliana). One ofthe faster-growing of the genus;reaches a height of 15-20cm (6-8in).It has elongated leaves which are dull bluish-green on the upper surface and purple underneath, and have prominent leaf veins. Responds well to some loam mixed with the gravel.
- Becketti. Often called C. cordata,
this plant occurs in two forms, each growing to about 18cm (7in) in height.One form has oval leaves, the other type elongated. Leaf color is olive-green, with a reddish-purple underside. Grows most rapidly underdog conditions, with foliage above water level.
- C. blassii. Beautiful specimen plant reaching a height of 40cm (153/4in) under good conditions. Has broad, pointed leaves up to 15cm (6in) long, carried on long stems. Upper surface ofthe leaf is dark green or reddish, underside crimson. Leaf surface is usually heavily dimpled. Grows best completely submerged and, once established, spreads rapidly. Grows well in hard or soft water, but does not tolerate very alkaline conditions.
- Ciliate. Large species, growing to about 40cm (153/4in). Leaves are of an elongated heart-shape, and are pale green, unusually for a Cryptocoryne.The plant will tolerate hard, alkaline water, and even slightly brackish conditions. For propagation, it is best grown as a bog plant in rich compost.
- Graffiti. Broad, bluntly pointed leaves are up to 7cm (21/4in) long, and carried on long stems to a height of25cm (10in). It is a very variable plant, and leaf coloring may be from pale green to dark-brownish green on the upper surface, with reddish-purple beneath. In some forms the leaves are attractively flecked with brown. Moving the plant causes leaf rot. Donor overcrowds.
- C. lingua. Small species growing to10cm (4in) high. Leaves are blunt-tipped, tapering into a flattened stem. Grows more rapidly as a bog plant. Do not expose to strong light, which stunts the growth. Prefers soft acid water.
- C. Neville. Occurs in several forms, notably the dwarf type, which grows to only 5cm (2in) in height. It is very useful as a ‘carpet’ plant for the foreground of the tank. Leaves armed-green, pointed and elongated. It grows best under bog conditions but, once established as a submerged plant, will spread steadily.
- Thwaitesii. Very attractive plant, up to 15cm (6in) high, whose leathery leaves have deeply serrated edges and are coloured olive or brown, mottled with dark brown on the upper surface. Grows very slowly, and may take two years to reach full size. Requires rich peaty compost.
- C. Wendi. Very popular plant found in various forms. Usually grows to about 20cm (8in), with leaves that are reddish-olive on the top, purple underneath, and have undulating edges. Smaller forms are also available. Relatively easy to propagate, and tolerates most water conditions.
- C. Willis. Sometimes misnamed. Undulate, this plant has narrow undulating leaves, reddish below and with an olive or brownish upper surface. Grows easily and quickly to about 25cm (10in). Spreads quickly to produce dense clumps.