Field madder

Scientific name: Sherardia arvensis L.

Family: Rubiaceae

MORPHOLOGY

Growth habit and size: Annual herbaceous plant, reaching a height of 5-20 cm.

Stem: Slender, prostrate-ascending stems, simple or branched at the base, quadrangular and rough-scabrous at the corners due to curved prickly hairs.

Leaves: The lower leaves are opposite, the middle leaves are whorled in fours, and the upper leaves whorled in sixes (2 x 5-8 mm). They are lanceolate, scabrous at the margins, mucronate, and tapering at the base, with a single nerve.

Flowers: Inflorescence in a terminal or axillary few-flowered head with 4-10 subsessile hermaphrodite flowers surrounded by a whorl of 6-8 bracts similar to the leaves. These bracts are scabrous at the edges, fused at the base, and exceeding the flowers. The calyx is bristly with (4)6 triangular and subulate teeth (0.3-1 mm), persistent and enlarging in the fruit. The corolla (about 4-5 mm) is actinomorphic hypocrateriform, pink-lilac, rarely white, with 4 acute lobes and an elongated cylindrical tube about 1.5 times the length of the lobes. It blooms from February to July.

Fruits and seeds: The fruit is a bilocular schizocarp (2-5 mm) composed of 2 mericarps fused at the base and crowned by persistent calyx teeth.

DISTRIBUTION AND HABITAT

It grows throughout Italy from 0 m to 1,900 m. It thrives in garrigues, fallow fields, pastures, grassy areas, and vineyards, often infesting crops.

USE

In the past, the red dye extracted from the slender roots of S. arvensis was used for dyeing fabrics. However, the yield was not sufficient to justify large-scale cultivation of the plant, and the color was not as bright as that obtained from Rubia tinctorum.

Photos: Kindly provided by Claudio Farinati