Two tropical plant species planted in the central house of the winter gardens are renowned for their large, showy leaves. These are taro, Colocasia esculenta and, arrowhead elephant’s ears or American taro, Xanthosoma sagittifolium.
At first glance, they look similar so how can you tell the difference between Colocasia and Xanthosoma? The key difference for identification is the shape of the leaf bases. The Xanthosoma leaf base has arrowhead-shaped lobes, with the leaf stalk directly joined at the notch.
In contrast, Colocasia leaves have a heart-like appearance with rounded basal lobes and the leaf stalk attaches just below the notch.
Another distinguishing feature for identification purposes is that the leaf surface of Colocasia esculenta has a smooth, green, silky, marble-like texture, whereas the Xanthosoma sagittifolium leaf surface has thick veins making it resemble elephant’s ears even more.
Our understanding of the potential size they can grow to was the motivation to give these giant beauties a bigger space in which to fully extend themselves. Their edible starchy corms were moved to the central bed last spring and were paired with the foliage of other interesting tropical species to create a tropical feeling under our deep southern sky.
Being heavy feeders, they require an abundance of water and food which is provided over the growing season which has resulted in these two taros graciously displaying their huge lavish foliage to great effect, enhancing the tropical landscape of the winter garden.
Garden Life is produced by Dunedin Botanic Garden. For further information contact Ben Xie.