Myong Gi Chung and Soon Suk Kang, "Morphometric Analysis of the Genus Hemerocallis L. (Liliaceae) in Korea." Journal of Plant Research, vol. 107, pp. 165-175 (1994).
S.S. Kang and M.G. Chung, "High Levels of Allozyme Variation within Populations and low Allozyme Divergence within and among Species of Hemerocallis (Liliaceae)" American J. of Botany, vol. 87 (11), pp. 1636-1646 (2000).
Alan W. Meerow, Michael F. Fay, Charles L. Guy, Qin-Bao Li, Faridah Q. Zaman, and Mark W. Chase, "Systematics of Amaryllidaceae based on cladistic analysis of plastid sequence data" American J. of Botany, vol. 86, pp. 1325-1345 (1999).
J. P. Tomkins, T. C. Wood, L. S. Barnes, A. Westman, and R. A. Wing, "Evaluation of genetic variation in the daylily (Hemerocallis spp.) using AFLP markers" Theoretical and Applied Genetics vol. 102(4) pp. 489-496 (2001).
Papers on Trillium by Shoichi Kawano and Co-workers.