Mycorrhizal Status of Two Hawaiian Plant Species (Asteraceae) in a Tropical Alpine Habitat: The Threatened Haleakala Silversword ( Argyroxiphium sandwicense subsp. macrocephalum ) and the Endemic Dubautia menziesii

Samples of roots and root-zone soil from the threatened species Argyroxiphium sandwicense subsp. macrocephalum and the endemic species Dubautia menziesii, both members of the Asteraceae, were collected in a tropical alpine area in Haleakala National Park, Maui, Hawai'i, and examined for arbuscular mycorrhizal fungi (AMF). All root samples exhibited the Paris-type of mycorrhizae with arbuscules produced on hyphal coils, and all soil collections included spores of AMF. Spores of Acaulospora, Entrophospora, Glomus, and Scutellospora spp. were recovered from this site.