'Geranium cuneatum'.
Source: Plants of Hawaii, Image 021003-0086 from http://www.hear.org/starr/plants/images/image/?q=021003-0086. http://en.wiktionary.org/wiki/File:Starr_021003-0086_Geranium_cuneatum_subsp._tridens.jpg
Author: Forest & Kim Starr