Cornaceae

Shrubs and small trees with opposite, entire leaves whose lateral veins curve forward to follow the leaf margin — the field character for the family. Break a leaf gently and pull the halves apart, and fine elastic threads of latex stretch between them; it is a reliable and rather satisfying identification test.

What look like large white flowers in the ornamental species are bracts surrounding a tight cluster of small true flowers. Fruits are fleshy drupes, edible in several species and important enough in two of them to be crops.

The family divides neatly into two medicinal traditions.

The astringent barks belong mainly to North America. Red-osier dogwood was among the most widely used antidiarrhoeal and wound remedies of Indigenous practice across the continent, and its inner bark was also a principal ingredient of kinnikinnick smoking mixtures. Cornus florida bark was used through the nineteenth century as a quinine substitute for intermittent fevers, particularly during the American Civil War when cinchona was blockaded — a use resting on bitterness and tannin rather than on any antimalarial principle.

The tonic fruits belong to East Asia. Cornus officinalis — shan zhu yu — is one of the more important herbs in Chinese medicine, a constituent of major kidney-tonifying formulas, and it is far better studied than any western member of the family. Cornus mas, the cornelian cherry, is both a European fruit crop and a herb with a growing metabolic literature.

Modern work on red-osier dogwood has come from an unexpected direction: it is being developed as a polyphenol-rich functional-food additive for livestock, which has produced feeding trials in pigs and poultry at a scale rarely available for a herbal material.

Two classes define the family. Iridoids — loganic acid, loganin, cornin, morroniside — are the bitter principles and the marker compounds, particularly concentrated in the C. officinalis and C. mas fruits. Hydrolysable tannins supply the astringency: ellagitannins and galloylglucoses, with gallic acid, ellagic acid and β-glucogallin as identified components.

Around them sits a conventional phenolic background of rutin, quercetin and kaempferol glycosides, chlorogenic acid and catechin. Anthocyanins colour the fruits of the edible species.