Cryptocoryne species (C. parva, C. wendtii, C. lutea, C. balanse, C. beckettii, C. willisii, C. Undulata)
Many Cryptocoryne species are very tough plants. They take awhile to settle into new tanks and may melt as they adapt to new tank conditions. However, they are very tolerant of low CO2 conditions which make them very suitable for non CO2 injected tanks. Easiest way to grow them long term without much fuss is by using a soil substrate. Cryptocoryne spread by either underground runners or a thick root tuber depending on the species. Baby plantlets that appear by the side can be uprooted and transferred to other positions in the tank.
Cryptocoryne comes in many colors and sizes. Cryptocoryne parva is among the smaller ones and grows less than 1.5 inches height. Others like C. undulata red has pretty copper tones to their leaves. Some C. wendtii varietals have attractive brown streaks. Many are tolerant of low light but should not be planted in shade, especially if you want them to grow well.
Compared to stem plants, they do grow to a maximum height (height depending on individual species). This makes them much easier to manage long term as they do not need to be pruned frequently. Their shorter height also makes them ideal plants for foreground.
Microsorum pteropus (java fern)
Java fern can be found in various tropical and subtropical regions in Asia. There are many variants available - Needle leaf variant (long, thin narrow leaves >40cm), Philippine variant (shorter leaves <15cm), 'Windelov' variant (branched leaf tips <20cm), narrow leaf variant (shorter leaves <15cm), 'Trident' variant (multiple lobes per leaf)
Microsorum pteropus develops a creeping rhizome on which the roots and leaves grow from. The rhizome can be attached to rocks or driftwood with string or glue, and after a few weeks it will attach naturally through its roots. It is one of the easiest aquarium plants to grow as it tolerates a wide range of water parameters and takes shading and crowding well. This means that it can be placed in almost any position in the tank. Due to its aesthetic similarity to land ferns, it matches driftwood very well, and this is where it is used most often.
Unlike what some folks presume, Java fern can grow well in high light levels though the leaves may grow to be slightly lighter green colored. Maintaining a clean tank with good plant health overall is essential in such circumstances to prevent algae. It can also be planted on aquarium substrate as long as the rhizome itself is not buried.
Even though it is a tough plant, it does grow much better if its basic needs are provided. Having enough NPK in the water column, and good all round fertilization gives faster, greener growth. General tank stability is also important as it is a slow grower and is slow to adapt to changes.
It can be propagated easily by dividing the rhizome of the plant. Baby plantlets also spawn on leaf edges now and then.
Java fern is easily attached to wood and is good for filling in spaces where there is no substrate to plant in.
Anubias barteri 'nana'
Anubias barteri 'nana' has been a long staple in the aquarium trade. It is hardy, and often sold attached to driftwood wood which allows easy placement in fish-only tanks as it doesn't require soil to grow. This also means that it can be moved around for alternate tank arrangements.
It is a slow grower that can take shade well. So many advantages in one plant! However, this does not mean that it is indestructible. Being slow growing means also that if its leaves are damaged through neglect it is slow to recover. Its leaves are also prone to algae if the plant is not growing well. As with java fern, even though it is a tough plant, it does grow much better if its basic needs are provided. Having enough NPK in the water column, and good all round fertilization gives faster, greener growth.
Anubias can be planted in almost any position in the tank, which gives it a lot of flexibility. As it can be placed anywhere, it is also often used to hide connection points between hardscape elements. It can also be used beneath larger/taller plants as it can take shading. Commonly it is used on wood/rock as a epiphyte.
There are a few different varieties; the smaller the varietal, the greater the cost usually. Anubias 'petite' has leaves around the size of a fingernail. While smaller varieties such as Anubias 'pangolino' has leaves half the size of small finger fingernail.
This plant is more commonly known as water sprite. It is actually an amphibious fern that is very hardy and fast growing. It has delicate light green leaf fronds, finer when compared to Hygrophila difformis (water wisteria) and can be grown free floating or planted in the substrate. It. This gives it very flexible placement though generally, it does grow tall with time. It has a much larger canopy with a small base, and can be placed in small pockets of soil/crevices to grow out from.
It does well in the mid ground and as a filler between shorter plants and taller hardscape. Larger sized leaves can be pruned off if they start shading surrounding plants.
Hygrophila difformis is more commonly known as Water wisteria to hobbyists. It is an aggressive growing stem plant that can be grown either planted or floating. It hugs the substrate when light levels are high and can be pruned into a (slightly large) bush. It has larger fronds/leaves compared to Water sprite and grows just as aggressively; it takes low CO2 conditions really well and this limits its growth rate somewhat which is good. In CO2 injected tanks it becomes far too weedy.
It can be used flexibly in the mid or background but needs pruning to be neat. Prune away leaves that grow in the direction you don't want them to grow and over time it can be shaped into a controlled bush.
Be careful about planting it too close to shorter plants as this plant spreads very readily and shades surrounding areas easily. For propagation, once it has reached a certain length you can cut at an internode and plant the cut end in another position.
Rotala rotundifolia is a reddish stem plant. It bends sideways when light is high and grows reddish leaves at the tips. It is more suitable as a background plant due to its height - it'll grow continually towards the water surface and will reach the top of most tanks. It can be shaped into bush form by regular trimming.
Trimming it will cause the lower portion to branch with new shoots. Over repeated trimming cycles, old stems deteriorate and should be removed; new shoot tips should be replanted. Be careful of using too many stem plants in a single aquascape as this increases the maintenance work required - more frequent trimming and replanting cycles.
Hemianthus glomeratus (Pearlweed)
Pearlweed is an undemanding small leaved plant that spreads aggressively in both CO2 injected and non CO2 injected aquariums. It is a green small leaf stem plant that will creep along the substrate if the light is high. It can be flexibly used in the mid or background and does not need a large space in order to root well.
It can be trimmed aggressively as it will sprout many side shoots from its internodes. This will create a nice bush over time. Its ability to fill in spaces and form dense bushes is the main reason why it is so popular in aquascaping. It's small leaf size and indistinct texture makes it great for naturalistic nature style scapes.
Propagation is easy; just cut at an internode and replant the top at a new position.
Vallisneria & Sagittaria species
Both of these genus are green 'tape grass' type plants that are all generally hardy and propagate by sending out runners. In hobbyist circles, 'Jungle Val' and 'Dwarf sag' are commonly available types. Vallisneria spiralis has a slight twist to its leaves while larger varietals such as Vallisneria nana and V. natans have leaves more than 50cm long. A shorter specie would V. 'Mini twister' at around 15cm and Sagittaria subulata 'pusilla'.
These plants can be foreground plants in non CO2 injected tanks as they generally have smaller/shorter forms without CO2 injection. Their texture is still a bit coarse for smaller tanks where Eleocharis species would be more suitable. They can be used as a background plant as well, especially the taller varieties. They spread naturally through underground runners. Baby plants can be uprooted and moved to other positions.
Nymphaea species (N. zenkeri, N. stellata, N. rubra)
Nymphaea species have attractive red leaves and are one of the easier species to maintain good, red form without CO2 injection. They grow aggressively if rooted in soil and bright light.
Their leaves do get large and shade surrounding areas so plant them in mind for future growth. This is one of the plants that often start small but can grow pretty large in time. It can be kept smaller by pruning away the oldest larger leaves as it grows. Their root system gets deep and is very large for matured plants. This means that once it grows in, most of the time you would not want to move it.
Mosses (java, flame, christmas, weeping, anchor)
There are a large variety of mosses available in the hobby and all of them are very easy to grow. Their usage in the aquarium exploded with the popularity of hardscape focused tanks. However, many folks with no hardscape experience shy away from them; either thinking that they are messy or hard to handle. They are actually very easy to use once you know how to.
Moss can be broken into smaller pieces, and each piece will grow if left in a area where there is light and flow. The easiest way to attach mosses to hardscape is by using super glue, which cures underwater in seconds. Most aquascapers use superglue rather than string to attach mosses as it is faster and more precise. You can also do this while the hardscape is already underwater in the tank. Take a small amount of moss on one finger, apply a small dab of gel super glue to the moss, then press it against the hardscape - hold for 5 seconds and the moss is attached. You do not have to worry about the orientation of the moss, it will grow towards the light in time. This works for every type of moss.
With this technique, it is easy to 'paint' entire surfaces with moss. Many hardscape focused aquascapes have very little soil; the aquascapers just attach moss to every surface.
Mosses also require regular trimming to keep them in shape; the part cut ends can be replanted elsewhere. With regular trimming, new growth orientates towards the light and looks neater.
This low-tech shrimp tank uses fissidens.
Here is the section for a detailed care guide for other aquarium plants.