Botanical Treasure #1. Wilkes collection type specimen: holotype of Argyroxiphium macrocephalum (US 59690)

From Plant Press Vol. 16 no. 2

The first botanical treasure is the holotype of Argyroxiphium macrocephalum (US 59690).

The large collection of over 8,000 plant specimens resulting from the U.S. Exploring Expedition (1838-1842), under the command of Lt. Charles Wilkes, was originally deposited in the National Institute for the Promotion of Science in 1844. These plant specimens were turned over to the Smithsonian in 1846 and constituted the foundation of the new national herbarium. The term National Herbarium arose only in 1894 when the Smithsonian merged the plant collections with those of the U.S. Department of Agriculture across the Mall, despite having no botanist to act as curator. Lester Ward, a paleobotanist, who was collecting modern material for comparison purposes, was the nominal custodian. Once combined, it was called the U.S. National Herbarium.

The Flora of the Hawaiian Islands website has images for many species, including Argyroxiphium sandwicense subsp. macrocephalum from Hawaii’s Haleakala National Park. (Photo by W.L. Wagner)

Argyroxiphium sandwicense DC. subsp. macrocephalum (A. Gray) Meyrat (≡ Argyroxiphium macrocephalum A. Gray), the Haleakala silversword, is listed as threatened by the U.S. Fish & Wildlife Service and as vulnerable on the IUCN Red List. Threatened by human vandalism and grazing by cattle and goats, wild populations are on the rebound due to high conservation attention. The Hawaiian endemic is restricted to a 1,000 hectare site in the crater and on the outer slopes of Haleakala Volcano on the island of Maui.