This section is from the book "British Wild Flowers - In Their Natural Haunts Vol5-6", by A. R. Horwood. Also available from Amazon: A British Wild Flowers In Their Natural Haunts.
The habitat of this plant is dry calcareous pastures, chalk and oolite hills. The plant is a hemi-parasite on the roots of other plants. The habit is prostrate. The rootstock is yellow, woody, the roots fibrous, with white suckers on the sides. The stems are branched, numerous, leafy, spreading in a circle. The leaves are linear, lance-shaped, obscurely nerved, yellowish-green, blunt or acute, slender, the upper leaves finely toothed, rough. The flowers are greenish-white, in leafy, tufted racemes on rough stalks, as long as or longer than the flowers, spreading in fruit, the angles rough. The bracts are rough, finely toothed, the lower middle ones longer than the flowers. The perianth-tube is funnel-shaped, short, open, the lobes triangular, bent inwards, spreading at the end, toothed in fruit. The fruit is green, egg-shaped, oval to oblong, longer than the persistent perianth, ribbed, netted, narrowed into the short, stout stalk. The fruit is a nut, i-seeded. The plant is 4-12 in. long, flowering from May to July, and is a herbaceous perennial.