Metrosideros collina (J.R. Forst. & G. Forst.) A. Gray var. prostrata Rock, Hawaii, Board Agric. Forest. Bot. Bull. 4: 61. 1917.
Type information:
Lectotype [BISH]. J. F. Rock 6097. 17 March 1910. Moloka`i: Kawela swamp, [back of Kamoku].
Lectotypified in H. St. John. Phytologia 42: 217. 1979. Isolectotype(s) [BISH! [2]].

Note: Rock included Hillebrand's unnamed gamma var. in this var. Additional syntypes: Kaua`i, [summit swamp of] Mt. Waialeale, 500-5200 ft., 24 September 1909, Rock 5087 (BISH! [2]); Maui, West Maui, summit of Mt. Puukukui, 5800 ft., August 1910, Rock 8145 (BISH!); Maui, bogs on top of Eeka, Hillebrand s.n. (B [PD], GH).

=Metrosideros polymorpha var. pumila
Note: Rock included Hillebrand's unnamed gamma var. in this var. Additional syntypes: Kaua`i, [summit swamp of] Mt. Waialeale, 500-5200 ft., 24 September 1909, Rock 5087 (BISH! [2]); Maui, West Maui, summit of Mt. Puukukui, 5800 ft., August 1910, Rock 8145 (BISH!); Maui, bogs on top of Eeka, Hillebrand s.n. (B [PD], GH).

*Verification: R.K. Shannon.