Hawaiian Silversword Alliance
University of Hawaii Botany Department

Last Modification: August 13, 2003

These materials are freely provided for instructional and educational purposes. Any duplication or publication of text or images herein for commercial gain without explicit written permission of the owner or photographer constitutes breach of trust and violation of copyright.
Gerald D. Carr

Each "thumbnail" image below is linked to a larger photograph.


What are silverswords and who cares about them?

Haleakala silversword, Argyroxiphium sandwicense ssp. macrocephalum. Larry, a.k.a. Gerry Carr, has been studying biosystematics, hybridization, and cytogenetics of the silversword and its relatives in Hawaii for the past 27 years. Moe, a.k.a. Robert Robichaux, has done extensive work on the physiological ecology, and more recently, population genetics of this group. Curly, a.k.a. Bruce Baldwin, has established the molecular phylogeny of the silversword group and its ties to North American ancestors that are sometimes called tarweeds. (photo 1991, Haleakala, E. Maui)
Chief guru of tarweedology Donald W. Kyhos inspects Dubautia arborea, a species that, in spite of its very distinctive appearance, hybridizes spontaneously with the Mauna Kea silversword. (photo 1976, near Pu'u La'au, Hawai'i)
Tarweed goo specialists (actually phytochemists) Bruce Bohm (l) and Bill Crins (r) pondering the constituents of the sticky exudates of Dubautia sherffiana, while Leslie Bohm (c) plans the next Thai restaurant stop. (photo 1986, Mt. Ka'ala, O'ahu)
Members of the tarweed subtribe (Madiinae) of the sunflower tribe (Heliantheae) of the aster family (Asteraceae), the Hawaiian silversword alliance consists of about 30 species in three genera (Argyroxiphium, Dubautia, and Wilkesia). The species exhibit an extraordinary range of anatomical, morphological, and ecological adaptations but are exceedingly closely related as judged by data from biosystematics and molecular studies. The evidence favors the conclusion that all of this diversity evolved from a single ancestor that colonized Hawaii by way of long-distance dispersal from North America. More information on adaptive radiation, hybridization, and evolution of this group is linked here. For further information and photos related to individual species, click on a genus below.
Want to know more?  Read the book! Missouri Botanical Garden Press

The Silversword Alliance Fully Illustrated

ARGYROXIPHIUM WILKESIA DUBAUTIA

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