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.
As with the other Dead Nettles there is no trace of this plant in ancient deposits. It is found in the North Temperate Zone in Europe and West Siberia. In Great Britain it is found in the Peninsula, Channel, Thames, Anglia, Severn provinces, and in S. Wales generally except Radnor and Cardigan. In N. Wales it is found generally except in Montgomery and Anglesea; throughout the Trent province except in S. Lincs; in the Mersey and Humber provinces, and in Cumberland. In Scotland it grows in Ayr and Westerness. It is local in the E. of Ireland.
Yellow Archangel is common in damp woods under hedges, especially those that overshadow ditches either by the roadside or in open fields. But it is most abundant under the trees in shady woods, copses, or plantations.
The stem is simple (or there may be several), erect, slender, square, smooth, with long lance-shaped leaves, coarsely toothed, veined, with or without long leaf-stalks, opposite, the leaves stiffly hairy, the upper egg-shaped, stalkless, the lower heart-shaped.
The flowers grow in whorls of from 6 to 12, and are yellow, blotched with red or pink. The calyx is acute and rigid. The corolla has a long, entire helmet, with the lower lip divided into 3 subequal lobes, and entire. The tube is short and swollen at the base below. The lower lip is spotted with red.
The plant is 1 foot high. It flowers in May and June, and is quickly over. It is worth cultivating, and is perennial, propagated by division.
The anthers and stigma mature simultaneously. The tube of the flower is 8 mm. long, and is expanded above for 2 mm., allowing the entrance of a bee's head. Where the honey is secreted at the base of the ovary it is smooth, but lined with hairs above. The stigma is branched, the lobes wart-like, and they diverge soon after the flower opens, but being mature they do not enlarge, but are more prominent afterwards. The tip of the lower division lies above the lower surface of the anthers. If the bee's back only presses lightly against the anthers, the stigma is not covered with pollen; but if it is a large bee, and presses the anthers firmly, the stigma gets covered with pollen from another flower. Afterwards the end of the lower lobe projects below the anthers, and is first touched by the bee. Pollen falls on the lower lobe of the stigma if bees do not visit it. The plant is visited by Bombus and honey-bees.
The nutlets are free, and when ripe fall to the ground below the parent stem, hence Yellow Archangel grows in wide patches in the woods or hedgerows.
This is a clay-loving plant growing on clay soil. Yellow Archangel is liable to be galled by Cecidomyia galeobdolontis. Two beetles, Meligethes symphyti, M. erythropus, are found on it.
Photo. Dr. Somerville Hastings - Yellow Archangel (lamium Galeobdolon, Crantz)
Galeobdolon, Dioscorides, is from the Greek gale, weasel, and bdolos, fetid smell.
The plant is called Yellow Archangel, Yellow Dead Nettle, Dunny Nettle, Weasel Snout.
Essential Specific Characters: 260. Lamium Galeobdolon, Crantz. - Stem erect, leaves ovate, acuminate, serrate, petiolate, flowers yellow, lower lip of corolla trifid, tube curved, fringed with hairs.