Corymbia ptychocarpa, commonly known as swamp bloodwood or spring bloodwood,[1] is a species of tree that is endemic to northwestern Australia. It has rough bark on the trunk and branches, broadly lance-shaped adult leaves, flower buds in groups of seven, creamy yellow, pink or red flowers, and barrel-shaped, ribbed fruit.
Corymbia ptychocarpa is a tree that typically grows to a height of 4.5to and has thick, rough, tessellated, brownish bark on the trunk and branches. It has the form of a crooked tree that tends to flop when young and often has drooping branches. Young plants and coppice regrowth have oblong to round or elliptical, later egg-shaped leaves that are long, wide and petiolate. Adult leaves are leathery, paler on the lower surface, broadly lance-shaped, long and wide, tapering to a petiole long. The midrib is pale yellow in contrast to the green lamina and the lateral veins are parallel to each other. The flowers are borne on the ends of branchlets on a branched peduncle long, each branch of the peduncle with seven buds on pedicels long. Mature buds are oval to pear-shaped, long and wide with a rounded to blunt-conical operculum. Flowering occurs from February to May and the flowers are creamy yellow, pink or red. The fruit is a woody, barrel-shaped capsule long and wide with about eight sharp ribs on the sides and the valves enclosed in the fruit.[2] [3] [4] [5]
Swamp bloodwood was first formally described in 1859 by Ferdinand von Mueller, who gave it the name Eucalyptus ptychocarpa and published the description in the Journal of the Proceedings of the Linnean Society, Botany.[6] [7] In 1995 Ken Hill and Lawrence Alexander Sidney Johnson changed the name to Corymbia ptychocarpa.[8]
In the same paper, Hill and Johnson described two subspecies and the names are accepted by the Australian Plant Census:
Corymbia ptychocarpa is found from the Kimberley region of Western Australia and through the Top End of the Northern Territory to near Doomadgee in far north-western Queensland. It grows in sandy soils and alluvium along watercourses and near springs. In the Northern Territory it occurs on the Arnhem Plateau, Daly Basin, Ord Victoria Plain, Pine Creek and the Victoria Bonaparte biogeographic regions.
Subspecies aptycha is restricted to the Top End between the Cobourg Peninsula, Yirrkala and El Sharana in Arnhem Land.[11]
It is also grown as a street tree in parts of Queensland, such as Cairns and Townsville.[2]