Pre-Pressing Treatment for Cissus quadrangularis L. and Other Small Succulents

Herbarium specimens of Cissus quadrangularis L. were prepared by different techniques and compared for shrinkage, retention of color, and persi- stence of stem appendages. The efficacy of three pretreatment techniques and two methods of handling succulent tissue were investigated. Using analysis of variance (ANOVA) there was shown to be a significant difference (P<0.005) between the three pretreatment techniques. Using the least significant diffe- rence(LSD) test, the deep- freezing technique was shown to produce less distortion in the resultant specimens than the gasoline technique (LSD=1.708) and the formalin technique (LSD=2.065). No significant difference was observed in the quality of specimens produced by the formalin and the gasoline techniques (LSD=0.357NS). ANOVAtest indicated a significant difference in efficacy between the acetic acid treatment, the longitudinal sectioning treatment and untreated specimens (P<0.001). The acetic acid pretreatment was shown to be superior to the longitudinal sectioning pretreatment (LSD=2.371) and untreated specimens (LSD=2.138). No significant difference was found between the untreated specimens and those subjected to longitudinal sectioning (LSD=0.233NS). The acetic acid pretreatment technique is recommended for treating specimens of small succulents by herbarium workers.