DENDROLOGY. 37 



COLLECTION AND PREPARATION OF SPECIMENS. 



It is desirable to have represented in the herbarium of the Forest 

 Service at Washington (which includes a collection of 

 woods) duplicate specimens of all species collected in 

 the different districts. The Washington herbarium is 

 a permanent reference collection used not only by the Forest Service, 

 but to a very great extent by other bureaus of the Department of 

 Agriculture. In order that the collection may be widely useful, it is 

 necessary that it "be made as comprehensive as possible. This can be 

 accomplished only by the combined efforts of all Forest officers. 

 Directions for collecting and preparing foliage, wood, bark, and other 

 specimens are given in the circular of March 5, 1910, prepared by the 

 dendrologist. 



The dendrologist will name and have mounted reference sets of 

 ^ * - * v. ^ tree and shrub specimens for each district. The work 



District herbaria. i i 11 TUT i j i 



can be done more economically in Washington than 

 in the district offices, which are not regularly equipped, nor does it 

 seem desirable to equip them, for such temporary work. The dried 

 specimens can be safely forwarded and returned bV mail under frank. 

 Duplicate specimens designed for the Washington herbarium should 

 be sent in at the same time. 



Collections of important forage plants are useful to familiarize 

 Forest officers with them and to enable them to obtain 

 P i?nt r s bariaofforase a knowledge of their uses, life history, and relation- 

 ship to other plant life of the National Forests. To be 

 fully useful, representative specimens should be collected and care- 

 fully preserved. They should be accompanied by notes describing 

 how each species grows, and particularly how much the species is 

 used for food by the stock. 



Unless good complete specimens are collected the material can not 

 be satisfactorily identified. Flowers, fruit, and mature foliage should 

 be represented in all sets of specimens gathered, while in the case of 

 herbaceous plants the specimens collected should include roots. If 

 such plants grow in bunches, enough of the clump should be preserved 

 to show the root habit. Before putting the specimen in the press, 

 the earth should be shaken, rather than washed, from the roots in 

 order to preserve the natural spread of the root system. If the plant 

 should be too large to he on a sheet 1H by 16^ inches, the stem may 

 be bent into an N or M shape, the angles being held in place by 

 strips of heavy paper or cardboard 2 to 3 inches long and ^ to 1 inch 

 wide, with a slit 1 to 2 inches long through the middle. One of these 

 slipped over the stem will hold the specimen firmly. 



Collected specimens should be placed between sheets of newspaper, 

 or preferably the plain, thin, collecting sheets interspersed alternately 

 with two or three sheets of blotting paper, and placed between boards 

 or a wicker press and subjected to a pressure of from 25 to 40 pounds. 

 This may be applied by tightly drawn straps or by a weight. Steins, 

 roots, and other parts of herbaceous plants over a quarter of an inch 

 thick should be thinned (by cutting) before pressing. The blotters 

 should be changed each day until the specimens are dry. 



At least two specimens of each species should be collected, in order 

 that one mav be forwarded to the Forester for identification. 



