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.
Stonecrop is found in the North Temperate Zone in Europe, North Africa, Siberia, but only at the present day. In Great Britain it is absent in Hunts, Cardigan, Mid Perth, Shetlands. It grows in Yorkshire at a height of 1500 ft.
Biting Stonecrop, or Wall Pepper, occurs wherever there are suitable ledges of rock, natural or otherwise. In wild hilly regions it grows on the shelving ledges of steep precipices, covering their angular edges like a green carpet turned golden-yellow in flower. It is also common on walls near villages, etc, being often planted, and on the ground where sandy stretches occur, being rather prevalent near the sea.
Rather dwarf compared with Orpine, this Stonecrop differs in other ways. It is a straggling plant with a small root, and several prostrate then ascending stems branching from a central one, with thick fleshy, cylindric leaves, egg-shaped, with a spur below, closely overlapping, alternate, swollen, and stalkless or sessile. The leaves are very numerous, and the second Latin name means bitter in reference to their taste, while the first has reference to their squat habit, seated as it were cushion-like on a rock.
Wall Pepper is distinct, in having yellow flowers, from the purple-and white-flowered Stonecrops. They are in 3-fid cymes, with blunt, swollen sepals, and petals twice as long, and spreading.
Three to six inches is the usual height for this pretty but diminutive species, which flowers in June and July. It is perennial, attractive, and suited for cultivation, and can be increased by division.
The plant is short, but the flowers are conspicuous on barren ground where it grows. It is proterandrous and contains honey, accessible to short-lipped insects, whence it is much visited. The honey is secreted in 5 yellow scales at the base of the flowers between the anthers and carpels. The flowers are cross-pollinated. When the flower opens and the petals spread into a star, 5 outer stamens alternate with the petals, and are erect, and now open in the middle of the flowers, and the 5 others are inclined outwards while the petals remain closed, and the stigmas are still immature. As the first stamens wither and turn outwards, the others rise up into the centre and open. Before the second ring withers and turns outwards, the stigmas ripen and stand in the centre. Insects remove the pollen before the stigmas are mature, but in dull weather the anthers are stored with pollen till the stigmas are ripe and may self-pollinate the flower.
Photo. J. H. Crabtree - Biting Stonecrop (Sedum acre, L.)
Insects touch the stamens and stigmas whether they settle in the centre or on the edge of the flowers. The flowers are visited by Bombus, Cilissa, Andrena, Sphecodes, Nomada, Prosopis, Megachile, Ammophila, Oxybelus, Eristalis, Pyrellia.
The follicle is many-seeded and opens above, and the seeds are dispersed by the wind.
Biting Stonecrop is a rock plant growing on barren rocky soil, or where there are stretches of sand or gravel derived from the more ancient granitic or schistose rocks.
A moth, Glyphypteryx equitella, is the only insect which feeds upon it, and no fungus attacks it, perhaps from its acrimonious properties.
The second Latin name refers to its bitter taste.
The plant is called Bird's Bread, Creeping Charlie, Creeping Jack, Creeping Jenny, Creeping Sailor, Crowdy Kit o' the Wall, Ginger, Gold Chain, Gold Dust, Golden Moss, Houseleek, Little Houseleek, Jack-of-the-Buttery, Moss, French Moss, Mouse-tail, Country Pepper, Poor Man's Pepper, Wall Pepper, Pepper Crop, Pig's Ears, Pricket, Prick Madam, Rock Crop, Rock Plant, Stancroppes, Stonecrop, Stone-hot, Stonnord, Wall Grass, Wall Moss, Wallwort. It was called Country Pepper and Ginger from its pungent flavour.
Biting Stonecrop was planted in gardens and used as a pot-herb.
Pliny said it produced sleep, for which purpose it was wrapped in a black cloth, and put under the pillow unawares. In the early days of herbals it was considered good for dropsy. It is emetic and has been used in scorbutic complaints.
Essential Specific Characters: 114. Sedum acre, L. - Stems in tufts, leaves blunt, imbricate, fleshy, sessile, spurred or gibbous at the base, flowers yellow, in a 3-cleft cyme, sepals gibbous below.