The leaves of Empleurum serrulatum, Ait., which species grows in Cape Colony, are occasionally found admixed with buchu leaves. They yield 0,64 p. c. of a volatile oil1), the odor of which reminds of rue and which is very different from that of buchu leaves; d 0,9464. It boils between 200 and 235°, mostly between 220 and 230°. With acid sodium sulphite this fraction yields a crystalline derivative, thus indicating the presence of methyl nonyl ketone, the principal constituent of oil of rue.