Plant specimens may be mailed to the herbarium either fresh or dried.
Fresh plant specimens should include stems, leaves, flowers, fruits, and seeds, or as much material as is available. Small plants can usually be sent intact, with roots and underground parts. Larger, woody plants (shrubs and trees) usually can be identified without including underground parts. The plant specimen should be placed in a small plastic bag, with a damp paper towel inside. Punch a few holes in the bag, and then seal it inside a box or manila envelope.
Here, a specimen is placed in a single fold of newspaper for pressing.
Pressed specimens are easy to make. Simply place the plant material inside a single fold of newspaper. Absorbent paper, such as paper towels, will be helpful, too. Sheets of cardboard may be placed on both sides of the specimen, or a homemade plant press can be used. Several pounds of weight should be placed on top of the cardboard in order to flatten the specimen as much as possible, and with few wrinkles. Care should be taken to replace the paper toweling each day, as it may become damp as the plant dries. Specimens dried this way are usually ready in about one week.
Lattice-style plant press with corrugated cardboard (for ventilation) and blotter papers. Paper towels can be substituted for blotters. Regular plywood (approximately 11" X 18") can be used in place of lattice. For tightening your press, regular hardware straps or tie-down straps work fine.