Herbarium specimens of plants are collected for a number of different uses. They can assist in accurate identification and provide a species record for a time and place that can be used in distribution maps. They can also provide biological material for researchers, a reference point to document scientific names and vouchers for research and seed collections. DNA barcoding, a new method of identification of plant vouchers, is being used in herbaria across the world. The Smithsonian National Museum of Natural History creates their barcodes from a short sequence of plant DNA, which can be easily identified from all healthy specimens of the species. This barcode is then printed and placed onto the plant mount. By creating these DNA barcodes, the process of organizing and loaning plant specimens becomes more streamlined and can be mechanized. Voucher specimens are select herbarium specimens. What distinguishes these specimens from others is that a voucher specimen is a "representative sample of an expertly identified organism." These specimens are usually associated with a professional research article and are considered to be more official references than a typical herbarium specimen. Voucher specimens can be useful in many ways such as use for comparison when scientists think they have found a new species or when dichotomous keys have narrowed the possible species down to a few that have minute differences. Plant collecting may also refer to a hobby, in which the hobbyist takes identifiable samples of plant species found in nature, dries them, and stores them in a paper sheet album, a simple herbarium, along with the information of the finding location, finding date, etc. necessary scientific information. As in many collecting hobbies, rarer specimens have been valued. However, when collecting living organisms, the conservation aspects must precede the collector's ambitions. This has led in some cases to a collector voluntarily taking part, helping scientists, in some research areas, provided he can store the "collectible". In fact, historically, many species have initially been found within a collection of a collector. Usually, a plant can be identified in nature, since they are stationary. The advent of digital cameras has led many plant collectors to switch totally to photography. Some have switched to collecting live specimens of various plant species in their gardens, building a sort of "private botanical garden". Some have specialized in a specific group, the orchids and the roses and their cultivars are among the most collected. Illegal collection of plants is known as plant poaching. A report on the risk of rare plant poaching has provided data showing possible connections between geography and the rate of poaching in the Shenandoah National Park, Virginia, USA.