Garden Pond Plants
This group has many promising species and varieties. The most important characteristic to consider with the selection of pond plants is size: many grow too large for use in aquarium enclosures. One should also be aware of dormancy requirements. Many of the pond plants described by vendors as “hardy” demand an extended cold winter dormancy, so they are less suitable for growing in a permanent indoor display. Those described as “tropical” are usually better choices. Some tropical to sub-tropical pond varieties, such as many of the flowering bulbs and dwarf taros, do require a dry season winter dormancy, but this can be accommodated by removing their planters to a cooler, dryer location for a few months.
Most pond plants will grow best with good air circulation and bright illumination. They look and prosper best in open-topped displays
Mexican Petunias (Ruellia brittoniana)
These very attractive plants are offered in two distinct growth forms. The erect “bluebells” types grow to 2-4′ tall and are similar to their wild progenitors. The semi-compact ‘Katie’ and similar cultivars grow as short bushes to about 10″. Flowers range in color from pink to light blue to purple.
Rain Lilies (Zephyranthes sp.)
There are many commercially-available species and cultivars in Genus Zephyranthes. While they are not especially appealing as foliage plants–most have sparse–onion-like leaves–their blooms are wonderful. Many of the garden varieties that grow well in ponds are pink or white in color. Others may be less hardy in saturated soils.
Sweetflag (Acorus gramineus)
Genus Acorus contains a few species of grass-like wetland plants. Most commercially-available sweetflags are cultivar varieties of A. gramineus, which is native to East Asia. These plants have a range of sizes and leaf colorations. The dwarf varieties (e.g., ‘Minimus Aureus’) are too small to be of much use in ripariums. Look for the selections that grow from 10″ to 15″ tall.
Houseplants/Tropicals
This is a very large group containing many plants that are clearly unsuitable for culture in wet environments. However, there are quite a few varieties and species kept as houseplants or tropical greenhouse specimens that adapt well to riparium environments. The best candidates among this group of plants are those that grow in wetland or riparian habitats in nature. A few such plants are common and readily available.
Peace Lily (Spathiphyllum)
Most of the cultivated varieties of Spathiphyllum originate from species that grow in swampy forests and similar habitats in the Neotropics (Central America and South America). Despite the ready availability of peace lilies as potted plants, there seems to be little readily-available information on their horticulture or ecology in nature.
Taros (Alocasia sp., Colocasia sp. and Xanthosoma sp.)
There are many species and varieties in the genera Alocasia and Colocasia, which originate from tropical areas in both the Old World and the New World. The natural habitats of many species include swampy forests or the banks of rivers. A few are widely grown for their starchy tubers, which can be cooked like potatoes, while others are popular as decorative plants. Taros have large heart-shaped leaves that can bear various rich colors and bold patterns. Some have very shiny leaves, while others have beautiful satiny sheens. Most grow too large for riparium culture, but among those grown in garden ponds or as houseplants are a few shorter-statured selections.
Dragon’s Tongue, Purple Waffle (Hemigraphis sp.)
Hemigraphis are readily available and likely to appear at any store that sells houseplants. The species H. exotica and H. repanda are the most common. Online sources describe them as originating from Southeast Asia. Many apparently occur in wetland habitats in nature. Most of the commercially available Hemigraphis have deep green leaves with purple or dark magenta undersides.
Aquarium Plants
This category includes many intriguing possibilities. Any planted aquarium enthusiast most likely already has several aquatic plants that will grow well as emergents in a riparium. Many plant species that can grow either in the air or in the water develop distinct leaf forms in each environment. Such plants equire some special care and adaptation periods to transfer from immersed to emmersed growth.
Some of the plants that are used in planted aquaria require high humidity for healthy emersed growth. These should be grown in an aquarium with a glass canopy that covers most of the top. Others, such as swordplants (Echinodorus sp.), prefer more air circulation and grow well in open-topped displays
Anubias (Anubias sp.)
All Anubias species can be grown as emergent plants. A few, such as A. gigantea actually have poor growth if kept in a permanently immersed state and are better candidates for emmersed culture. The wide range of sizes of Anubias species offers many possibilites their use in riparium composition. Short-statured, low-growing kinds (e.g. A. barteri ‘Nana’) serve well in the display midground, while tall, erect species (e.g. A. afzelii) function well in the background or as centerpiece plants.
Crypts (Cryptocoryne sp.)
This is a large group containing many species with potential for riparium culture. The Cryptocoryne are already beloved aquarium plants: as a group they are perhaps the most popular of all. Their species diversity, wide range of forms and the general hardiness of many crypt species contribute to their frequent application in underwater displays. The same traits have led to the growth of an intriguing pastime among some aquarium hobbyists and tropical plant fanciers, the tending of Cryptocoryne in emersed culture. In their native habitats, most crypts pass at least part of the year growing above water.
Water Hyssops (Bacopa sp.)
A half-dozen or so Bacopa species are commonly used in planted aquariums. Their small, neat, rounded leaves function well as accents and as a means to soften transitions between groups of larger, bolder plants. Most Bacopa are easy to grow and can be kept either as underwater or emersed plants. The most common aquarium species, B. monnieri, transitions readily when switched between these two conditions, although humidity should remain high while it adjust to emersed growth.