This is a cultivar of Citrus sinensis (L.) Osbeck. For details of the Sweet Orange see Citrus sinensis  ‘Chinese Oval’. The following description is of a blood orange still grown in Western Australia in the early 20th century. ‘Maltese Blood. The pulp is streaked and mottled with red. It has few seeds. Tree thornless and of dwarf habit, and may be planted closer than freer growing kinds; hardier than the Washington Navel, and the tree a more generous bearer. The foliage is dark and glossy. Fruit small to medium, oval, of high flavour; a good keeper and carrier.’ [Despeissis p.237/1903].