Arillastrum is a monotypic genus of trees in the myrtle family, Myrtaceae, containing the single species Arillastrum gummiferum. It is endemic to southern New Caledonia. Like several other genera related to Eucalyptus, it is called a eucalypt. It is a tree up to 35 meters tall with a trunk over a meter wide. It might flower only every seven years. The flowers each have four clusters of stamens and staminodes. This species grows on ultramafic rock substrates. It grows in stands with other individuals of its species.