Bulletin - United States National Museum - Smithsonian Institution

FLORA OF WASHINGTON AND VICINITY. 219
of saving these, aud to press only a part of what has been collected, for
several specimens of everything should be taken if they can be found.
A temporary label should be written for each plant as it is reached,
placed with it, and kept with it throughout. If there is more than one
specimen, the temporary label will be needed for the duplicates when
the other specimen is mounted. The label should give the Latin name
of the plant, if known, or if only the generic name is known, then this
should be written, the date of collection, and the particular locality,
both habitat and station, or at least the latter. Any special fact
observed in connection with the plant may also be written on the label.
This done, the next step is to press the specimens.
The following is my own method of pressing plants:
The prei^s consists of two pine boards 1 inch thick, 12 inches wide,
18 inches long, and dressed, having each two cleats on one side, one
across near each end. Upon one of these a pile of plants is built.
For drying i>aper, after trying many different kinds, I have finally
adopted ordinary cheap brown wrapping-paper. The size used is 10
by 16 inches. It would perhaps be better to be larger. The double
sheets (two leaves) are kept separate, by which means the thickness
between each specimen may be varied ad libitum. Four or five sheets
is the usual thickness for ordinary plants. These are placed upon the
lower press-board (cleat side down), and upon them is laid a sheet of
thin white paper a little larger than the brown paper. This paper
is a firm but very thin manila, a little heavier than tissue-paper, but
good tissue-paper would answer. Upon this sheet, which is single,
the plant to be pressed is laid ; its leaves are laid out neatly, and all its
parts are placed in the position in which it is desirable for them always
to remain. This done, a second sheet of thin white paper is laid over the
plant ; then another layer of four or five double sheets of the brown pa-
per is laid on. Upon this another sheet of white paper is then laid,
another specimen placed upon it and arranged for final disposition,
another sheet of white pajier laid over that, and another layer of brown
paper upon that. This process is continued until the portfolio is emptied.
Several things are to be observed as the work of preparing the speci-
mens for pressure progresses. The amount of brown paper used should
be made to vary somewhat according to the nature of the plant.
Grasses and grass-like plants require much less; succulent plants
require more; thick-stemmed plants need thick layers of paper, more
to preserve the even surface of the pile than on account of the amount