This section is from the book "Wayside And Woodland Blossoms", by Edward Step. Also available from Amazon: Wayside And Woodland Blossoms: A Guide To British Wild-Flowers.
Lamium purpureum. - Labiatae. Perfoliate Honeysuckle (L. caprifoliuni) is similar to the last, but the upper pairs of leaves are joined together by their broad bases. The corolla-tubes are longer than in the common species, and it therefore becomes impossible for even the longest-tongued bees to carry off much of the honey. Moths with their long trunks can; and consequently they swarm upon it at night, and carry the pollen from plant to plant. This species may be found in copses in Oxfordshire and Cambridgeshire, but is believed to be only naturalized - not a true native. Flowers May and June. The name Lonicera was bestowed by Linnaeus in honour of a German botanist named Adam Lonicer.
Our forefathers, when giving English names to plants, found it by no means easy work, and the greater number of our native species they left unnamed altogether. Many of the names they did invent were made to serve many times by the simple expedient of prefixing adjectivea Thus, having decided on Nettle as the distinctive name of certain stinging herbs (Urtica), they made it available for the entirely unrelated genus Lamium by calling the species Dead (or stingless) nettles. In a similar fashion they made Hemp-nettle, and Hedge-nettle.
Apart from the resemblance in form of the leaves in certain species, there is little likeness between Lamium and Urtica, the large and graceful flowers of the former contrasting strongly with the inconspicuous green blossoms of the stinging nettles (see page 103). In the absence of flowers the difference may be quickly seen by cutting the stems across, when Urtica will exhibit a round solid section, whilst Lamium is square and tubular. The flowers, like those of Bugle (page 21) and Meadow-Sage (p. 23) are labiate, and are produced in whorls. The calyx is tubular, with five teeth. The corolla tubular, with dilated throat, whence the name from Laiinos (Gr.), throat. The British species are five:
I. Red Dead Nettle (Lamium purpureum). Leaves heart-shaped, with rounded teeth, stalked. Bases of flower-bracts not overlapping. Corolla purplish-red. Whole plant often purple. Hedge-banks and waste places. April to October.
II. Intermediate Dead Nettle (L. intermedium). Intermediate between the first and the next species, but more robust. Bracts overlapping. Teeth much longer than calyx-tube, spreading. Cultivated ground, not in S. of England. June to September.
III. Henbit Dead Nettle (L. amplexicaule\ Calyx more hairy than in I. and II.; teeth equal to tube in length, converging when in fruit. Corolla slender, deep rose-colour, often deformed. Bracts broad, overlapping. Waste places. April to August. Above three species are annuals, the remainder perennials.
IV. White Dead Nettle (L. album). Corolla large, creamy white, upper lip vaulted. Caiyx teeth long. Waste places. March to December.
V. Yellow Archangel (L. galeobdolon). Corolla yellow, the lower lip orange, spotted with brown. Hedges and woods. May and June.