The plant is about two feet in height, and somewhat resembles a cowslip or an auricula. It belongs to the natural order Boraginaceæ, and is nearly allied to the lungwort, viper’s-bugloss, borage, and forget-me-not, all of which exhibit color changes more or less distinct. The various species of Myosotis, or forget-me-not, are also called scorpion grasses, from the upper flower-bearing portion of the stem being curled on itself like a watch-spring. The cluster of flowers, forming the inflorescence of Arnebia, develops in same scorpioid fashion. There is a double row of flower buds on the curled stalk, and as this gradually unwinds pair after pair of the flowers expand in succession. In shape and color the individual flowers are not unlike those of the primrose, though rather smaller. When a flower first opens, five conspicuous jet-black spots are seen upon the yellow rim of the salver-shaped corolla. If the flower be examined the following day, we are surprised to discover that the black spots have vanished as if by magic. The yellow of the corolla is also much paler, and a little later on presents quite a bleached and silvery appearance, the petals becoming almost white. No sooner have the spots disappeared from the first pair of flowers than a second pair expand, and display their sable marks in bold relief upon the yellow enamel of their petals. From this time onward the inflorescence comprises both kinds of flower, those but newly opened having the five conspicuous spots, and the older ones on which no spots are visible. From these dark spots--the so-called finger-marks of Mahomet, Arnebia has received its name--the Prophet-plant. Its flowers seem bewitched, the change is so pronounced and obvious; a day or two after unfolding they differ so much from the newly opened ones beside them, that were they growing on separate plants, we should at once set them down as belonging to another species.