And here they are…
Cladophora aegagropila
Sometimes called Lake Balls or Marimo Balls, these fascinating little guys are not really plants at all, but spheres of dark green algae (yup – even algae can be decorative!). They are normally found in shallow lakes, where the movement of the waves forms them into perfect spheres, and there they happily roll back and forth filtering nutrients from the water. Due to the action of photosynthesis, they rise to the surface during the day and sink back down at night. The Japanese government have actually designated them as a special national treasure and given them legal protection from harvesting.
In the tank they must be turned regularly to keep them in shape, but if you prefer they can instead be allowed to spread out and form a lush green carpet over the bottom. This looks especially lovely covering river rocks. Kept in a spherical shape however, there are very few plants to rival this one for structural impact or interest in the aquarium. Best of all, despite their exotic appearance they are incredibly undemanding and easy to grow.
Summary of care:
Care Level: easy
Availability: can be hard to find though I have seen them for sale a few times. Tropica Plants stockists may have them.
Cost: varies depending on availability but often quite expensive.
Max height: 10 cm
Max width: 10 cm
Growth: very slow
Goldfish Edibility Rating: not known but may be nibbled at, seeing as GF like algae.
Requirements:
Light level: very low to very high
Temperature: 5-28 C
pH: 6 – 8.5
Hardness: medium – very hard
Nutrients: not required
CO2: not required but does respond to added CO2
Water movement: does not mind water movement (will roll along the bottom if there is enough current), but do not place right underneath very strong flows as these may tear the sphere apart.
Planting: simply drop into the aquarium. Do not bury in the substrate.
Maintenance: none, except to turn over regularly if a perfect spherical shape is wanted.
Propagation: Divide original plant into smaller pieces and either roll these into spheres or allow to grow flat.
Anubias barteri var. nana ‘petite’
This is the smallest of the Anubias family and first appeared as a mutation in a Singaporean nursery. It is a delightful little plant, ideal for miniature aquascapes in small tanks. Bushy in habit, it has oval leaves which are a bright, fresh green when they first appear and darken gradually as they get older. Like all Anubias, it needs to be attached to wood or stones and doesn’t like having its roots buried in the substrate. (Watch out for a special feature on Anubias next month!)
Summary of care:
Care Level: easy
Availability: can be hard to find. Tropica stockists will probably have it however.
Cost: varies depending on availability but usually not expensive.
Max height: 5 cm
Max width: 10 cm
Growth: very slow
Goldfish Edibility Rating: not known, but may be eaten
Requirements:
Light level: very low to high
Temperature: 20-30 C
pH: 6 – 8
Hardness: very soft – very hard
Nutrients: not required, but does better with some added fertiliser
CO2: not required but does respond to added CO2
Water movement: does not mind some water movement but strong flows may bruise the leaves
Planting: Attach the rhizome to rocks or bogwood using cotton or fishing line until it has rooted itself firmly. Do not bury in the substrate.
Maintenance: None
Propagation: Will produce baby plants from the rhizome; gently separate these from the parent plant and attach elsewhere in the aquarium.
Java Moss (Vesicularia dubyana)
Java Moss is a firm favourite with goldfish owners due to the distastefulness which stops it becoming an instant salad bar! This incredibly hardy and undemanding plant is absolutely ideal for beginners as it tolerates virtually any conditions and is almost impossible to kill. It is best grown on rocks, bogwood and can even be used to conceal tank equipment as it will happily grow on any surface. Besides its unusual appearance which provides visual interest in the aquarium, it also has a useful place in breeding and fry-raising tanks, as the tiny fry will seek sanctuary in its thick, gently waving fronds.
Summary of care:
Care Level: very easy
Availability: commonly available
Cost: inexpensive.
Max height: 5+ cm
Max width: 5+ cm
Growth: slow
Goldfish Edibility Rating: distasteful, rarely eaten
Requirements:
Light level: very low to very high
Temperature: 15-28 C
pH: 5.5-9
Hardness: very soft – very hard
Nutrients: not required
CO2: not required but
Water movement: does not mind some water movement
Planting: attach to rocks, bogwood etc. using fishing line or cotton until it has firmly rooted itself. Do not bury roots in substrate.
Maintenance: none, except to trim occasionally with scissors to keep in shape
Propagation: Will produce baby plantlets from the rhizome; remove these from the parent and attach elsewhere in the tank.
Cryptocoryne parva
Smallest of the Cryptocorynes, this sweet little plant originated in Sri Lanka. It has long, pointed, mid-green leaves on graceful stems, and is absolutely charming planted in groups around a piece of bark or driftwood. It needs more light than other Cryptocorynes so don’t let it be overshadowed by other plants. It is ideal for very small tanks, or as foreground plants in larger aquascape designs.
Summary of care:
Care Level: fairly easy - medium
Availability: can be hard to find. Tropica Plants stockists will probably have it however.
Cost: varies depending on availability but usually inexpensive.
Max height: 10 cm
Max width: 7 cm
Growth: slow
Goldfish Edibility Rating: not known, but Cryptocorynes are rarely eaten
Requirements:
Light level: medium to very high
Temperature: 20-29 C
pH: 5.5-8
Hardness: very soft - hard
Nutrients: not required but does well with some added fertiliser
CO2: not required but does respond to added CO2
Water movement: keep away from strong flows; a gentle current is best
Planting: plant individuals into substrate a few centimeters apart; in 6 months they will form a cohesive low group of plants.
Maintenance: remove the odd yellowed leaf.
Propagation: Plant reproduces by runners so will spread naturally; if a separate group is wanted then remove outside plants from parent runners and root elsewhere in tank.
How did that happen hun?! 
I dunno why it's so hard to find round here.... anyone else in the UK manage to get it?