Canned Plants: The Park Service's New Deal Vasculum

It looks like a green lunch tin with "NPS" painted on the side. It is a vasculum — a container botanists carried into the field to keep freshly picked plants in good shape until they could be pressed, dried and preserved. The one in the National Park Service History Collection, used at Rocky Mountain National Park, has a second story too: it was made by young New Deal workers.

Vasculum made by the NPS Western Museum Laboratories, about 1939–1941, and used at Rocky Mountain National Park. Credit: NPS History Collection, HFCA 2770.

A botanist's tin can

Vascula (the plural) hold plant specimens during fieldwork until the collector can study, press and mount them — or, sometimes, replant them somewhere new. Metal vascula are documented from the late 1700s, though the word caught on only in the early 1800s, and by the 1850s they were standard botanical gear. They came in many shapes; a cylindrical can carried horizontally was popular. They stayed in use until the mid-1900s, when cheap, lightweight plastics spread after World War II. Most botanists today use plastic containers or zipper bags.

Ned Burns, chief of the NPS Museum Division, explained how to use one in his 1941 Field Manual for Museums, forerunner of today's NPS Museum Handbook. He valued park herbaria but warned that "collecting is an art in itself and should not be attempted by the uninitiated." Within two hours of headquarters, wet newspaper wrapped around the plants might do, but "a vasculum is the best receptacle in which to carry specimens for a few hours," and for longer trips he advised both a vasculum and a plant press.

Original paper label inside a vasculum made by the NPS Western Museum Laboratories. (HFCA 2770)

Made by the New Deal

The collection's vasculum was made by Civilian Conservation Corps (CCC) and National Youth Administration (NYA) enrollees at the NPS Western Museum Laboratories (WML) in Berkeley, California. With this New Deal labor, the laboratories produced equipment for park natural science collections: cabinets for bird and mammal skins, geology specimens, insects and plants; plant presses; traps for birds and small mammals; celluloid tubes for specimens; and boxes for skulls. Most were free to parks, though cabinets usually cost the price of materials, and the WML also mounted herbarium specimens for free.

The vasculum as advertised to parks in the 1939 catalog Miscellaneous Products Available to National Parks and Monuments*. Credit: NPS History Collection, HFCA 1645.*

The first WML vasculum was a special order for Glacier National Park. From January 1939, the laboratories offered it to all parks in their catalog: "made of heavy-gauge sheet metal reinforced at all edges… Forest green color. Adjustable shoulder straps," and "comparable in quality to regular vasculums for sale at biological supply houses."

Why herbaria matter

In a herbarium, plants are flattened in a press, dried (often in an oven) and sewn or glued to thick acid-free sheets, or stored in packets, with labels giving the scientific name, collector, date and place. A specimen usually includes stems, leaves, flowers, fruits and sometimes roots, and with proper care can last for centuries.

Each specimen proves that a species grew in a particular place at a particular time. Specimens help scientists describe new species, confirm identifications and study how species are related, and they document where plants grow and with what, when they flower and fruit, how populations and ranges change, threats to rare and endangered species, biodiversity, the effects of habitat loss and climate change, and the history of collecting in an area.

Hundreds of national parks hold more than 3.5 million specimens of plants, conifers, ferns, mosses, liverworts, algae, lichens and fungi. Yellowstone's oldest date to 1899, and many parks have collections from the 1910s and 1920s. Many have been photographed or scanned and can be viewed in online databases run by the Park Service, universities and states.

Sources

Based on "50 Nifty Finds #48: Canned Plants," NPS History Collection, National Park Service; a work of the United States government in the public domain. The original cites Baker (1958), Burns (1941), Lewis (1993), the Western Museum Laboratories' 1939 catalog and NPS National Catalog statistics (2024). Pictures an earlier version of this page left out were restored on 2026-09-26.