The plant kingdom is a very diverse group of living organisms that has had millions of years to evolve. Many odd-looking forms have arisen to fill ecological niches that other plants do not take advantage of. This has lead to some interesting shapes and designs created by nature. Many of these plants have been introduced into cultivation and are available for the ornamental gardener.
Monkey Puzzle Tree
"It would puzzle a monkey to climb this tree," remarked a 19th century Englishman about this odd-looking ornamental tree, and the common name has persisted ever since, so the myth says. The monkey puzzle tree (scientific name Araucaria araucana) is an evergreen conifer tree native to Chile. It grows to 70 feet tall and 35 feet wide. The most interesting characteristic of this tree is the odd look of the leaves. They are stiff and triangular-shaped and are actually primitive forms of needles. One of its closest living relatives is the Norfolk Island pine and numerous fossils of similar species have been found dating back to the time of the dinosaurs.
Monkey puzzle tree likes full sun in USDA zones 7B through 11. It needs a well drained soil but is not picky about soil types. It prefers regular water but is drought resistant.
Tropical Pitcher Plant
The tropical pitcher plants, members of the genus Nepenthes, are native to southeast Asia. They are a carnivorous plant that feeds on insects to supplement the poor nutrition of the rainforest. Nepenthes have long strap like leaves that grow from a central vine. At the tip of the leaves they produce a tendril that eventually grows into an odd-looking, hollow, tube-like pitcher with a cover. Just under the cover is a nectar gland that attracts their prey. When an insect lands to feed on the nectar, it will lose its footing and fall into the pitcher below. Digestive enzymes in the pitcher slowly dissolve the prey.
Tropical pitcher plants like bright diffused light and may only be suitable for greenhouse or terrarium culture outside of their natural habitat, although some people have had success cultivating them as houseplants. Most Nepenthes do best between 55 and 95 degrees Fahrenheit, with a 10 to 15 difference in day and night temperature. Species originating from highland areas need slightly cooler nights. They can be planted in loose, well-draining potting mix. Nepenthes need to stay moist and should not be allowed to dry out, but also should not be allowed to remain wet. A constant high humidity level above 50 to 60 percent is required for them to thrive.
Not all of the pebbles scattered around the southern African deserts are actually rocks. Some are odd-looking plants, living rocks. They are members of the genus Lithops and have developed a way to avoid predation by mimicking the natural stones in their habitat. The plant consists of two rounded, succulent leaves joined together with a cleft between them. In their natural habitat all but the very top of the plant is buried to conserve water in the 120 degree heat. The glassy looking top of the plant is modified to channel light into the leaf for photosynthesis.
In cultivation, these ornamental plants do best when not fully buried to the top. Plant them in a well-draining soil or cactus mix and place them in full sun. Water the plant only after it has dried out. Living rocks make a great southern exposure houseplant.