18:^ 



A CONVENIKNT J.A1H)RA1Y)KV IM.ANT I'liKSS.' 



H. S. .Ia( Kso.N, riirduc Univor.sity. 



The drying of plants is at best a laborious and uninterestinK. though very 

 necessary phase of the making of an herbarium and in the preservation of 

 plants for illustrative or elass study pur])oses. The old system of chang- 

 ing dryers has, in large part, given way in recent years to more modern 

 and time saving methods. The introduction of the use of corrugated 

 strawboard between the dryers au<l the utilization of some source of 

 aititicial lieat for drying the ]>lants- has taken much of the drudgery 

 from the old methods and in general has resulted in a better quality of 

 herbarium material. 



The writer has used a simple, type of plant press during the past ten 

 years whicli has proven very practical and satisfactory for general lab- 

 oi'atory purposes. On accomit of the simplicity of construction and the 

 low Initial cost of this apparatus it has seemed desirable to furnish a 

 description of it with specifications and illusti-ati(ms for the benefit of 

 those who may not have solved the problem of drying plants to their satis- 

 faction. 



The first press of the sort to be described was constructed in 1911 for 

 use in the laboratories of the Department of Botany and Plant Pathology 

 at the Oregon Agricultural College. From one to four of them have been 

 in constant use there since that time both for general laboratory pur- 

 poses and for use in connection with classes in taxonomic botany. The 

 writer has also used, since 1915, presses of similar construction in the 

 P.otanical Department of the Purdue Agricultural Experiment Station. A 

 number of persons from other laboratories who have seen these presses 

 in use at one or the other of these institutions have adopted a similar type. 



The apparatus consists essentially of a box with rack on which the plant 

 press rests, provided below with a source of heat (Fig. 1). The box is 

 15 by 18^^ inches, inside measurement, and is open at top and bottom. 

 It may be made square 18i/l> by IS^A inches if desired. The sides are made 

 of one inch boards, ten inches wide and fastened together with screws. A 

 rack on which the press rests (Fig. 2) is provided and placed three inches 

 from the top of the box. This is made of material one inch square and 

 is fastened all the way around the inside of the box. One or two cross 

 pieces are added as illustrated, though are perhaps unnecessary. Yellow 

 poplar lumber is foimd to be very satisfactory as it is not so liable to warp 

 as some other kinds. 



Heat may be conveniently supplied by two or three carbon filament 

 electric light bulbs, the sockets for which are fastened about three inches 

 from the bottom. Two sixteen candle power lights are sutticient for ordin- 

 ary purposes, depending somewhat upon the succulence of the plants to be 

 dried. It is well, however, to provide three sockets placed in such a way 

 as to give the most imiform disribution of heat. The writer has also 

 used, with entire satisfaction, special heating units of low resistance so 



'Contribution from the Department of Botany, Purdue University Agricultural 

 ExiKTiiiient Station. 



"Riker, P. L«., Directions for collecting Plants. Bur. PI. Ind. U. S. Dept. Agr. 

 Circ. 126:27-35. 1913. 



