The tribulus2217 grows nowhere except in marshy places: though held in abomination elsewhere,2218 it is employed on the banks of the Nilus and Strymon as an article of food. It always bends towards the water, and has a leaf like that of the elm, with a long stalk. In other parts of the world there are two varieties of this plant; the one2219 with leaves like those of the chicheling vetch, the other with leaves protected by prickles. This last variety blossoms also at a later period than the other, and is mostly found in the hedge-rows about farm-houses. The seed of it is black, rounder than that of the other, and enclosed in pods: that of the other variety bears a resemblance to sand.
Among the prickly plants there is also another kind, known as the “anonis:”2220 indeed, it has thorns upon the branches, to which leaves are attached similar to those of rue, the stem being entirely covered also with leaves, in form resembling a garland. It comes up in land that has been newly ploughed, being highly prejudicial to the corn, and long-lived in the extreme.