Picris

“All these appearances were more easily seen in a leaf of Picris treated in the same manner; for in this milky plant the stems and middle rib of the leaves are sometimes naturally colored reddish, and hence the color of the madder seemed to pass farther into the ramifications of their leaf-arteries, and was there beautifully visible with the returning branches of milky veins on each side.”

A History of Science: in Five Volumes. Volume IV: Modern Development of the Chemical and Biological Sciences

“(_Hesperis matronalis_), of the hawkweed (_Picris hieracioides_), of the rough hawksbeard (_Crepis biennis_), and others.”

Species and Varieties, Their Origin by Mutation

“Helicrysum, a biennial of the Vasse district, is a grateful fodder for horses, and the Morna nitida for goats, sheep, and cattle, as are also several species of Picris and other shrubs.”

The Bushman — Life in a New Country

“All these appearances were more easily seen in a leaf of Picris treated in the same manner; for in this milky plant the stems and middle rib of the leaves are sometimes naturally coloured reddish, and hence the colour of the madder seemed to pass further into the ramifications of their leaf-arteries, and was there beautifully visible with the returning branches of milky veins on each side.”

The Botanic Garden A Poem in Two Parts. Part 1: the Economy of Vegetation

“From these experiments the upper surface of the leaf appeared to be the immediate organ of respiration, because the coloured fluid was carried to the extremities of the leaf by vessels most conspicuous on the upper surface, and there changed into a milky fluid, which is the blood of the plant, and then returned by concomitant veins on the under surface, which were seen to ooze when divided with scissars, and which in Picris, particularly render the under surface of the leaves greatly whiter than the upper one.”

The Botanic Garden A Poem in Two Parts. Part 1: the Economy of Vegetation