Three-cornered (or triangle) palms (also known as Dypsis decaryi) are small but highly ornamental palm trees from Madagascar, where they grow in open areas and forests as well as in rainforest, where the few remaining trees are endangered but protected. They are however widely grown as ornamentals in many climates, including Toowoomba. Three-cornered palms are unique among palms in that the leaves spiral upwards in three distinct ranks. The leaf bases are swollen, overlapping, with white waxy bases, and the rather few leaves on each plant are pinnate, stiffly erect with slightly arching tips, about three metres long and white to green, without basal spines. The sparse stiffly erect leaves with drooping tips give this elegant palm its very distinctive outline. The leaflets are long and narrow, and taper to a fine point. The lowermost leaflets on each side of the leaf develop very long (up to two metres) fine thread-like reins (see photo), a characteristic also found in some other palms.
The trunks of three-cornered palms are 30-40 centimeters thick, greyish and rather rough, and the old leaves dry out on the trunks then fall naturally. This leaves untidy trunks and usually the old leaves are cut away for tidiness, sometimes leaving the bases to accentuate the triangular effect. In nature the palms grow 10-15 meters tall, and although they are easy to cultivate and grow quickly when young they only reach 5-10 metres in cultivation. Established trees are very drought tolerant but need some moisture and require deep rich free-draining soils for best growth. They require a frost-free location.
I only know of two specimens in Toowoomba, one in the front garden of St Mark’s Church in High Street, Rangeville, and one between Matthews Street and Lillian Court in south-west Toowoomba which is visible over the fence beside the eastern drive-through beside the Philharmonic Society Hall in Mathews Street (see photos below). No doubt there are others in the city,
Three-cornered palms grow well in Toowoomba, are of striking appearance and only moderate size, and should be more widely grown in our parks and gardens. The very similar teddy bear palm (Neodypsis lastelliana) has a distinct crown shaft which is densely covered with fuzzy brown hairs.
|The three-cornered palm trees in gardens in Lillian Court (left) and in High Street, Toowoomba (right)|