BRIEFER-ARAICLES 
TISSUE TENSION IN AMORPHOPHALLUS 
(WITH ONE FIGURE) 
Large monocotyledonous plants which do not develop woody 
mechanical tissue afford excellent opportunity to demonstrate the ten- 
sion to which cortical and central tissues are subjected. The combined 
result of the stretching of the cortex and the compression of the central 
tissues is the rigidity of the organ. 
Fic. 1.—Leaf of Amorphophallus campanulatus 
Such a plant in the Philippine Islands is Amorphophallus campanu- 
latus (Roxb.) Blume (Araceae). The decompound blade may often be 
more than a meter above the ground and occasionally spreads out over 
an area 1.5~2 meters in diameter. The stemlike petiole, which is often 
10 cm. in thickness, is the part utilized in studying tissue tension. 
Two sets of experiments were performed. In the first set, medium 
sized petioles were collected in the middle of a hot day, when the plant 
Was partly flaccid, brought into the laboratory, and there experimented 
upon during the following hour. In each case a piece 30 cm. in length 
and as nearly uniform in thickness as possible was selected from the 
petiole. A strip of the cortex, 1 cm. wide, was taken from one side of ° 
235] [Botanical Gazette, vol. 60 
