W. D.  Clayton, ?Notes on the genus Digitaria Haller. Studies in the Gramineae?, Kew Bulletin, vol. 29, pp. 517-525, 1974.

W. D.  Clayton, ?A discriminant function for Digitaria diagonalis. Studies in the Gramineae: XXXVII?, Kew Bulletin, vol. 29, pp. 527-533, 1974.