Rare Plant Field Techniques and Specimen Preparation - NYS Dept. of Environmental Conservation

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Rare Plant Field Techniques and Specimen Preparation

Rare plant field techniques are similar to those of most scientific botanical excursions except the focus of the trip is to find rare plants. Some have likened it to the botanical equivalent of an Easter egg hunt or the unraveling of a mystery!

Pre-trip Planning

Before the trip begins, thorough background material must be assembled and studied. If needed, plant lists and site details can be obtained from the Natural Heritage Program botanists. If the plant being sought is not a familiar one, consult field guides, plant experts, and herbarium specimens to understand the habitat and important morphological characters needed for identification. This will help form a "search image" in the mind. It is also important to know if there could be any look-alike plants at the site and how the look-alikes differ from the target species. A good knowledge of the flora of your search area will help tremendously.

Past sightings or collections, topographic maps, soil and geology maps and/or aerial photographs are consulted to determine where the search will take place. It will help if you have experience reading topographic, aerial, geologic, or soil maps on paper or within a GIS, including Google maps and similar mobile apps. Each map has its own symbols, colors, and pattern signatures that should be familiar to you. After the site is selected landowners are contacted, beforehand if possible, to obtain permission to visit the site. Sometimes permission can only be obtained after arriving at the site and talking to the landowner. Any other people familiar with the site are contacted to see if they can contribute additional information such as parking and trail access or recent changes in the vegetation.

The Search

After arriving at the site, field equipment is unloaded and decisions are made about where to begin the search. This is based on time, size of the area, topography, and trail accessibility. Care should be taken to assess the difficulty of the terrain and proximity to assistance to determine if you are able to do the work alone or if someone should go with you for safety reasons. Searches are conducted by walking in a sweeping pattern that will cover as much of the likely habitat as possible.


During the search, notes should be taken about the type and condition of the habitat and its characteristic species. The community type, if known, and the three dominant plant species of the canopy, shrub layer, and herb layer should be recorded. If rare plants are found, then documentation of the rare plant occurrence takes place. The most important things to document are: location of the plants, the habitat and associated species, numbers and condition of the plants, the characteristics of the surrounding landscape, and any past or current threats to the survival of the plants. Another very important part of the documentation is to make a sketch of the immediate area with obvious, long-lasting landmarks, such as permanent natural features, roads, trails, buildings, etc. An arrow indicating north is a must. A sketch of the site with the route taken is the easiest way to relocate an occurrence. If a global positioning system (GPS) unit or GPS app is available, it is especially useful to record GPS points and a track, especially in UTM NAD83 coordinates, if the plant is in an area with few landmarks. Finally, a specimen, photograph, or sketch should be made of the plant. If the plants are not found, it is very important to note the reason why. This may save search time if attempts are made to relocate the plants. You may record the information in the online Rare Species Reporting Form (see link on the right side of this page).


Collections can be made only with the permission of landowner. This may entail obtaining collection permits, if the land is managed by government entities or conservation organizations. If there are enough plants available where a collection won't affect future reproduction, it is important that a specimen be collected and the identity confirmed by a Heritage botanist. It will then be deposited at the New York State Museum or one of the large regional herbaria. Specimens can be collected in a container in the field (i.e. plastic bags, vasculum, field press) and later transferred to a folded sheet of newspaper. The specimen should be neatly organized on the newspaper so that all leaves are flat. At least one leaf should be flipped over to show the underside. The newspaper should be pressed between two sheets of corrugated cardboard with blotters and placed in a plant press or under heavy books. Careful pressing of the plant will result in the highest quality preserved specimen suitable for deposition in any herbaria. Allow the specimen to dry completely and include the following collection data, preferably typed on a 3x5 piece of paper: species name and location information, including: state, county, town, nearby village and specific plant location including GPS points if taken; habitat with associated species; number of plants; and any field characteristics that may not be seen on a dried specimen (flower color, habit, tree dimension etc.); date of collection; collector(s); collection number, if used; and who identified the specimen. Pack the plant between two sheets of cardboard, or in a cardboard box if multiple specimens, and mail to the Heritage Program along with an online Rare Species Reporting Form (see link on the right side of this page).


Photographs or sketches should be made if there are only a few plants or as an addition to the specimen. Photos and sketches are useful to show natural colors, habit (erect, drooping, clumping etc.), and habitat. A close-up lens can be useful to record small parts of the plant that confirm its identity. Digital photos are preferred and can be e-mailed to a Heritage Program botanist or attached to the online reporting form.

After the search is complete, a note should be sent to the landowner detailing your findings.

Typical Equipment List

  • field notebook or electronic entry (mobile phone, tablet)
  • 10x hand lens
  • field guides - especially for separating unexpected look-alikes (see annotated bibliography of plant guides and manuals (PDF) (266 KB, 17 pages))
  • pencils
  • compass
  • GPS unit
  • county road map as a backup to cell service
  • topographic maps and/or aerial photos
  • small tape measure
  • colored survey tape - to mark location or route if necessary
  • camera equipment
  • plant specimen containers and plant press
  • small post-it notes for separating collections or for folding over small parts of flowers that may fall off (e.g. sedge fruits)
  • whistle - in case of trouble
  • cell phone and backup battery
  • first aid kit, repellants, and sunscreen
  • binoculars (especially for cliff species)
  • food and water
  • proper field clothes
  • walkie-talkies - if you go with other people to areas without cell phone service and expect to become separated from them
  • leave word with someone where you will be going in case you don't return on time