Plant of the Month

plant of the month

Elephants Amongst Us

‘Tropicals’ were once a group of plants found only in southern regions of the United States or in locations where the temperatures never came remotely close to freezing!  Fortunately, during the 1970’s gardens such as Wave Hill in NYC started to look at Tropicals in a new light and began to incorporate them into more conventional displays of annuals, container gardens and even mixed borders.  One group of Tropicals that are readily available for the temperate garden, yet still garner comments of “Wow, look at that!” is the Elephant Ear.
Elephant Ear is the common name that actually describes plants in three different genera:  Alocasia, Colocasia and Xanthosoma.  All three genera have large sagittate or arrow-shaped leaves that – growing upwards of 3’ long and 2’ wide – resemble the size and shape of an Elephant’s Ear!  Elephant Ears are members of the Araceae or Arum Family and initially most of these plants were grouped under the genus Colocassia.  The name Colocasia originated from the Greek Kolokasion, originally the name for the edible root of Water Lotus, Nelumbo nucifera.  It was the Greek physician and botanist Pedanius Diosorides (40-90 AD) who first used Kolokasion to describe the edible corm of Colocasia in addition to the Lotus root.  In 1753 Carl Linnaeus first penned Colocasia as a species epithet when he described Arum colocasia and Arum esculentum.  In 1832, the Austrian botanist and Arum specialist Heinrich Wilhelm Schott (1794-1865) reclassified these two species as Colocasia antiquorum and Colocasia esculenta respectfully.  Colocasia esculenta, also called Tarro, was originally native to the wetlands of Malaysia and has been renowned for its edible root and leaf for over 7,000 years!  In fact, the species epithet comes from the Latin Esculentus, meaning edible.  Oddly, all the species of Colocasia, Alocasia and Xanthosoma are poisonous if eaten raw due to high concentrations of calcium oxalate.  The plants are rendered palatable by boiling or steaming the tissues, significantly reducing or eliminating the chemical.  Colocasia consists of around 25 species that are native to tropical Polynesia and SE Asia.  Of the numerous cultivars available, ‘Black Magic’ has wonderfully attractive, powder-purple leaves while ‘Teacup’ has the most intriguing, cup-shaped foliage available for the Garden.
Alocasia is also native to tropical and subtropical Asia and E. Australia and is composed of roughly 70 species.  It too can have foliage of an imposing size and many of the species are also edible when properly cooked.  Although this genus initially resembles Colocasia, there are several noteworthy differences.  Alocasia prefers well-drained soils, shade and the leaves are typically oriented upwards.  Colocasia thrive in full sun, especially in moist soils or even standing water and the leaves are pendant.   The etymology of Alocasia is suspected to simply be a variation on Colocasia.
The third member of the trilogy, Xanthosoma differs from the previous two in that it is native to Central and South America, with one of the more common species being Xanthosoma sagittifolium.  Originally named Arum sagittifolium by Linnaeus, it was once again Schott who reassigned it to its present status!   The name Xanthosoma comes from the Greek xanthos, meaning yellow and soma meaning body, referring to either the stigma coloration or the yellow inner tissues while the species epithet once again refers to the arrowhead-shaped foliage.  Just as with Colocasia esculenta, both the roots and the leaves serve as a popular food source.  For the garden, ‘Lime Zinger’ and ‘Chartreuse Giant’ are two selections that provide large, lime-green leaves that both enhance the texture and brighten a garden.  For all three genera, additional fertilizer with an even moisture supply will guarantee rapid summer growth.  All three can also be overwintered by bringing the container in for the winter and reducing the watering to impose dormancy.  Or, simply allow the plants to be frosted, dig the corms, wrap them in newsprint or lightly moistened peat and set in a cool basement for the winter.
This arum trio is all about the fun of adding bold Tropical Texture to your garden – after all, who would not crave having some resemblance of an Elephant in their Garden!