Railliardia platyphylla A. Gray , Proc. Amer. Acad. Arts 5: 134. 1861.
Type information:
Lectotype [US]. U. S. Expl. Exped. s.n.. 1840. Maui: East Maui, on banks of crater.
Lectotypified in G. Carr. Allertonia 4: 105. 1985. Isolectotype(s) [GH! [photo F!], K!, NY [photo F!], US!].

Note: As "Raillardia." Sherff (1935) cited two sheets as type; Carr designated one of the two as lectotype and the other as isolectotype.

=Dubautia platyphylla
Note: As "Raillardia." Sherff (1935) cited two sheets as type; Carr designated one of the two as lectotype and the other as isolectotype.

*Verification: R.K. Shannon, W.L. Wagner; Carr, G.D. 1985. Allertonia 4:1-123.

Railliardia platyphylla A. Gray var. leptophylla Sherff, Amer. J. Bot. 20: 619. 1933.
Type information:
Holotype [GH]. J. F. Rock 8578. October 1910. Maui: Haleakala, on Pu`unianiau Crater. Isotype(s) [BISH! [6], [photo F!], F!, GB!, GH!, K!, NY!, UC!, US!].

Note: As "Raillardia". Photo of holo at F!.

=Dubautia platyphylla
Note: As "Raillardia". Photo of holo at F!.

*Verification: None.

Railliardia platyphylla A. Gray var. trillioidea O. Deg. & Sherff, in Sherff, Amer. J. Bot. 28: 30. 1941.
Type information:
Holotype [F]. O. Degener , E. Ordoñez and & F.C. Salucop 12425. 7 August 1939. Maui: [East Maui, Haleakala], S of Kaluanui, on dryish talus. Isotype(s) [B!, F!, GH! [4], NY [3, mfc!], PTBG!, US! [3]].

Note: Present det. by G. Carr, 1986.

=Dubautia platyphylla
Note: Present det. by G. Carr, 1986.

*Verification: R.K. Shannon.