Curator Finds, Names New Species of Climbing Milkweed

A new species of climbing milkweed has been named by Alexander Krings, curator of the North Carolina State University Herbarium (also NCSC, its international Index Herbariorum abbreviation). The species – Gonolobus tenuisepalus Krings – was first collected in the tropical rainforests of southern Costa Rica while Krings was a graduate student in the Department of Forestry.

“The flowers are tiny (about 6-8 millimeters in diameter), purplish to dark brownish-red and borne in very dense, umbellate clusters,” said Krings. “Although a number of congenerics occur in Costa Rica, its apparently closest relative is known from Mexico. Based on the mildly fetid fragrance, it is likely pollinated by flies.”

Climbing milkweeds constitute one of the most species-rich and interesting groups of vines in the world. Highly advanced, members exhibit a startling array of highly modified flowers. Pollen is borne in removable sacs called pollinia – a trait that has evolved in only one other plant family: the orchids.

“New discoveries such as this highlight the continued importance of herbaria – collections of dried, pressed, mounted, and labeled plants,” said Krings. All plant species names are governed by an international code of nomenclature. One of the most important requirements of the code is that a physical specimen must be designated for each new species described. This specimen serves as the voucher for the name and is considered the “type” specimen. As each botanical name must be linked to a type, the herbaria of the world maintain literally millions of type-specimens as the basis of all plant names.

Typical of research herbaria, the NC State Herbarium also maintains a collection of type specimens. Founded in 1898, NCSC is maintained by the Department of Botany and serves in a teaching, research, and extension capacity. A brief history, as well as links to its type catalogue, can be found at: http://www.cals.ncsu.edu/botany/ncsc/history.htm.