Nearly any tropical plant can grow in a terrarium, but only certain species will truly thrive and stay small enough that they will never need to be transplanted. Many of these plants help support popular terrarium animals, providing food, oxygen and shelter, but it's not necessary to have an animal present; several terrarium plants are worth growing for their exotic beauty alone.
A fast-growing epiphyte, or "air plant," Dischidia bengalensis is ideal for beginners or new terrariums. It flowers almost all year long, and can either be planted or mounted within the terrarium. They are often sold attached to a piece of cork. The peach-colored flowers are shaped like small lanterns and grow in clusters. The long leaves look similar to flat seed pods. It is part of the milkweed family, and in India is considered an invasive species because of its aggressive growth. Contained in a terrarium, however, it provides striking color and texture.
Codiaeum variegatum, or dwarf croton, grows up to 18 inches tall, although its normal-sized counterpart can reach up to 10 feet tall in ideal outdoor growing conditions. It has wide, tongue-like leaves that grow outward similar to a yucca plant, and displays many variegated colors, such as red and green, yellow and green, and orange and green. As a tropical plant, Codiaeum variegatum requires constant temperatures and humidity; it will die if temperatures drop below 50 degrees F.
For unusual flowers and low-light conditions, it's hard to beat the Dorstenia turnerifolia. The flowers are a deep, blackish-purple and have thick, meaty petals. The leaves are long and spiky, and the plant typically grows about 12 inches tall. Native to Brazil and the Amazon rainforests, Dorstenia turnerifolia requires high humidity, but will thrive without much light.
Also known as artillery plant, Pilea microphylla can spread rapidly and cover a large area. It reaches about 12 inches tall and has small leaves that give it an appearance similar to a fern. The light green color of Pilea microphylla contrasts well with the typical dark green of many other terrarium plants. Pilea microphylla does well in high humidity, but requires moderate to high amounts of light.
With many varieties and colors, Neoregelia is a popular terrarium plant for its bright colors and ability to easily reproduce itself. Some of the more popular varieties for keeping in a terrarium include compacta, lilliputiana, ampullacea (also known as "midget"), olens, red waif, fire ball and red bird. Many of the varieties have thick, long reddish leaves and grow 10 to 12 inches tall, with the exception of midget and lilliputiana, which grow only 3 to 4 inches tall. All require high amounts of moisture and humidity, and prefer medium light.