The relationships of this family with other plants remain uncertain, and the family has been placed in different orders by different authors, including Lamiales (in the Cronquist system) and Solanales (Dahlgren system). Molecular phylogenetic publications have grouped the Lennoaceae within the clade "Euasterids I", and most recently, it was subsumed into the family Boraginaceae in the APG II system .
The family comprises up to three genera, Ammobroma, Lennoa and Pholisma, which between them hold around five species, including the desert christmas tree, Pholisma arenarium and sandfood, Pholisma sonorae .
Members of this family are succulent, herbaceous plants with no chlorophyll . The leaves are reduced to short scales, and the plants are entirely parasitic on the roots of their hosts, which are typically Clematis, Euphorbia, and various woody Compositae .