This section is from the book "British Wild Flowers - In Their Natural Haunts Vol2-4", by A. R. Horwood. Also available from Amazon: A British Wild Flowers In Their Natural Haunts.
Mercury as it was called, once so commonly a kitchen-garden weed, or herb rather, has no record in the ancient past to indicate its more than recent origin. It is found to-day in the Temperate Northern Zone of Europe and in Siberia, and has been introduced into N. America. It is not found in Cardigan, Mid Lanes, W. Highlands except the Clyde Islands, in the N. Highlands except in Ross and E. Sutherland, and not in the N. Isles, but elsewhere from Caithness to the south coast; up to 1200 ft. in the north of England. It is common in Ireland and the Channel Islands.
Good King Henry was so often cultivated at one time as a salad that it is now not uncommon near houses, and indeed it is to be found usually in one or more spots, at least, in every village, as well as in towns, growing in or near the churchyard, or within or hard by the yard of a farmhouse or other dwelling. It is almost always in evidence also on waste ground of every description.
The stem is erect, pyramidal, with widely-spreading branches or leaves below, tapering above. The leaves are flat, succulent, angular, on long, furrowed leaf-stalks, arrow-shaped or triangular, mealy below, bright-green, entire, and succulent. The stem is covered with wartlike projections, and has alternate red and green bands.
The flower is green. apetalous, the flowers being compound, with a corolla arranged in a terminal tapering spike, leafless, with a hollow, membranous calyx, and a long stigma which is bipartite, acute, and white. The fruits are smooth, exceeding the perianth.
This plant is usually about 1 ft. high. It flowers in May up till August. It is perennial, and can be propagated by division. It is cultivated as Spinach.
Good King Henry has very long styles and from 2-3 anthers, and is proterogynous, the stigma ripening before the anthers. Like other species it is anemophilous, or pollinated by the wind. The fruit is a utricle which falls when ripe, or being enclosed in a membranous calyx is wafted some distance away by the wind.
Being addicted to a sand soil it is a sand-loving plant, and being cultivated is improved by humus.
Photo. A. R. Horwood - Good King Henry (Chenopodium Bonus-henricus)
Like other Goosefoots it is infested in summer by several bugs, e.g. 4 Heteroptera, Piasina quadrata, Lopus sulcatus, Calacoris cheno-podii, Orthotylus flavosparsus, and a Homopterous insect, Trioza chenopodii.
The name Bonus-Henricus, Fuchs, is a translation of Guter Hein-rich, or Good Henry, given it by the Germans.
This plant is called All-good, Blite, Smear Dock, Flowery Docken, Mercury Docken, Fat Hen, Good Henry, Good King Harry, Mar-kerry, Mercury, English, False and Wild Mercury, More Smere-wort, The Roman Plant, Shoemakers' Heels, Smiddy Leaves, Wild Spinach.
Markerry was "used as a Spinach and always called Markerry". In Flowery Docken, probably "flowery" is intended from the mealy leaves. In regard to the name False Mercury, Gerarde says: "It is taken for a kinde of Mercurie but improperly, for that it hath no participation with mercurie, either in forme or qualitie, except yee will call every herbe mercurie which hath power to loose the bellie". "It is a common proverbe among the people, Be thou sick or whole, put mercurie in thy Koale". The name Smear-wort refers to its use as an ointment. Smiddy Leaves "indicates the observation of one of its favourite habitations, viz. the nigh vicinity of the blacksmith's workshop".
It was formerly used for wounds and to cleanse old ulcers. It has been and is still used as a Spinach, until the foreign variety was introduced.
Essential Specific Characters:265. Chenopodium Bonus-Henricus, L. - Stem erect, leafy, simple, leaves sagittate, entire, triangular, mealy, flowers in terminal spikes, stigmas long, fruit exceeding the perianth.