(en) V. L. Chopra et Markandey Singh, Ornamental Plants for Gardening, Scientific Publishers, (ISBN978-93-86237-79-8, lire en ligne), p. 82.
(en) James Cullen, Sabina G. Knees, H. Suzanne Cubey et J. M. H. Shaw, The European Garden Flora Flowering Plants: A Manual for the Identification of Plants Cultivated in Europe, Both Out-of-Doors and Under Glass, Cambridge University Press, (ISBN978-0-521-76151-2, lire en ligne), p. 284.