Dubautia carrii and D. hanaulaensis, New Species of the Hawaiian Silversword Alliance (Compositae, Madlinae) from Molokai and Maui

Dubautia carrii B. G. Baldwin & Friar and D. hanaulaenNis B. G. Baldwin are new species in Dalmatia Gaudich. sect. Railliardia (Gaudich.) G. D. Carr (Compositae, Madiinae) of the Hawaiian silversword alliance that were previously treated within the circumscription of D. linearis (Gaudich.) D. D. Keck subsp. apposita (Sherif) G. D. Carr. The two species are allopatric, with D. carrii in mesic to wet shrubland and forest on eastern Moloka'i and D.). hanaulaensis in mesic shrubland and forest on southern West Maui. Although closely resembling D. linearis subsp. linearis and linearis subsp. (H. Mann) G. D. Carr in habit and capitulescence characteristics, D. currii and D. hanaulensis differ from Ficoll subspecies of D. linearis in the sense adopted here by having consistently opposite (rather than variable) phyllotaxy and toothed (rather than entire) leaf apices, and by occurring in mesic or wet (rather than mostly (dry) habitats. Dalmatia carrii and D. hanaulaensis are highly similar morphologically; they commonly differ from one another in stature, stem vestiture, leaf shape, capitulescence size, and receptactilar-bract glandulosity Molecular phylogenetic data indicate that D. carrii is most closely related to the East Maui endemic species of Dalmatia sect. Railliardia (i.e., D. menziesii (A. Gray) D. D. Keck, D. platyphytta (A. Cray) D. D. Keck, D. reticulata (Sherif) D. 0. Keck, nut D. waianapanapacmcis G. D. Carr), and D. hanaulaensis represents an early-diverging lineage within the Maui (Big Island) clade of Dalmatia sect. Railliardia. High similarity of D. carrii and D. hanaulaensis ill morphology and ecology may reflect retained ancestral or plesiomorphic slides shared with the common ancestor of the Maui clade of Dalmatia sect. Railliardia, a lineage otherwise known for exceptional adaptive radiation.