COLLECTING ECONOMIC PLANT DATA 35 



Large fleshy fruits sometimes can be sectioned either crosswise or 

 lengthwise, both if possible, and the sections then pressed and dried. 

 In such cases, a sketch or photograph of the fresh fruit is desirable. 

 Large woody fruits often can be divided lengthwise with a hacksaw to 

 leave half attached to the stem. If too large they had better be cut off 

 and kept separately. 



Fleshy plants are sometimes difficult to dry, but dipping them momen- 

 tarily into boiling water will overcome the problem. Small cacti may be 

 split and the juicy interior removed. Larger cacti should be photo- 

 graphed, or sketched, and only sections or segments pressed. 



Delicate flowers like morning-glories, orchids, violets, or iris can be 

 prevented from shriveling and collapsing during the drying by placing 

 pieces of cellophane over and under the flowers. Cellophane is useful 

 also to prevent juicy fruits or stems from sticking to the newspaper. 



Loose flowers or fruits can be added to the sheets as extra material 

 for future dissection and study, particularly if these parts are scanty on 

 the specimen. Such loose pieces should be enclosed in a small envelope 

 or piece of paper, properly numbered. 



Badly wilted plants usually can be revived by immersing them for a 

 few hours in cool water. Material that has dried up entirely sometimes 

 can be salvaged to make presentable specimens by soaking in warm 

 water. Afterward the excess water is drained off and the plants pressed 

 as usual. 



Drying Methods 



Drying may be accomplished either by sun or by artificial heat. Sun- 

 dry:'ng is most common, but, during inclement weather and in humid 

 climates, artificial heat must be used. Artificial heat, when properly 

 employed, is to be recommended as a uniformly dependable means for 

 making perfect herbarium specimens under all conditions of climate or 

 weather. Rapid diying is essential in producing good specimens with 

 well-preserved colors. Fading occurs in improper and in slow drying, 

 leaving the specimens unattractive in appearance and uniformly dull 

 brown in color. 



Artificial heat can be supplied in a number of ways. One highly suc- 

 cessful method for the field consists in suspending a filled press above a 

 small lamp-stove, with a canvas skirt wrapped around the press and 

 extending to the floor to conserve and direct the heat up through the 

 corrugations of the ventilators. These lamp-stoves burn kerosene and 

 have a 2-inch wick; some types have two wicks. With ordinary care, 

 there is no fire risk, but the wicks must be kept trimmed with scissors 

 to prevent smoking, and the canvas must not touch the stove. Ap- 

 parently these lamp-stoves are now difficult to find in the United States, 

 but formerly they were available in the larger cities of Latin America. 

 Ordinarily, kerosene barn lanterns should serve in place of the lamp- 

 stoves, but under tropical conditions two lanterns under each press 

 might be necessary to produce sufficient heat. 



Portable, gasoline pressure stoves can be used, but there is danger, 

 not only of developing too much heat and setting fire to the press, but 

 also of generating gas fumes, which lead to explosions, especially if the 

 stoves are confined in a room with little or no ventilation. Furthermore, 

 constant vigilance is necessary to maintain the pressure in the reservoir. 



