This section is from the book "Sub-Alpine Plants Or Flowers Of The Swiss Woods And Meadows", by H. Stuart Thompson. Also available from Amazon: Sub-Alpine Plants: Or, Flowers of the Swiss Woods and Meadows.
A tall species 2-3 feet high, with erect and often branched stem, hairy and glandular at the top. Lower leaves broadly oval, obtuse, cordate at the base, softly downy on both sides, crenate-dentate and petioled; upper leaves lanceolate, sub-sessile. Flowers in a long, irregular spike. Bracts lanceolate, entire, often reddish. Calyx-teeth lanceolate and ending in a white mucro. Corolla dull purple. See plate and interesting notes by J. W. White in his excellent Flora of Bristol (1912).
Mountain woods. July, August.
Central and Southern Europe, except the Mediterranean region; Caucasus. In England on the Cotswold Hills only.
A much smaller and more fragile plant 1-2 feet high, green, hairy, and scented, with almost woody stock and many ascending stems. Leaves hairy and green on both sides, oblong-lanceolate, very shortly petioled. Flowers pale yellow, in loose whorled spikes. Calyx-teeth hairy, triangular, half length of the tube.
Waste places and limestone hills, extending to the Alps. June to September.
Central and Southern Europe, Asia Minor, Caucasus.
Readily distinguished from the last by its deflexed leaves, which are oblong-lanceolate and nearly glabrous.
An annual weed in cultivated land, often seen in fields in the sub-alpine region. June to August.
Europe, Asia Minor, Caucasus. British.
Is another annual weed often seen in the lower Alps. Leaves narrow, on short stalks, downy. Stem square, often much branched. Leaves narrow, linear-lanceolate, shortly petioled. Flowers purple, red, or rarely white, large. Calyx greyish, hairy, with long but unequal teeth. Very polymorphic.
Cultivated and uncultivated ground, walls, etc.; common. July to October.
Europe, especially Central and Southern. British.
Cymes usually many-flowered. Calyx 5-toothed. Corolla-tube usually with a ring of hairs within; upper lip short, notched; lower lip 3-lobed. Stamens 4, exserted. Anthers divergent.
About 30 species inhabiting the Old World and Australia.
Stem 3-12 inches high, densely leafy, erect, simple, woolly. Leaves decreasing in size upwards, the lowermost very large. Leaves obovate-lanceolate or oblong, obtuse, slightly serrate, wavy or entire, more or less pilose like the bracts; lower leaves narrowed into a leaf-stalk; upper leaves sessile, passing into ovate, often obscurely 3-lobed bracts, even the uppermost bracts twice as long as the flowers. Bracts often with a violet tinge. Flowers pale azure-blue, collected into whorls towards the summit of crowded spikes.
Pastures and Alpine woods up to 7000 feet. June, July.
Carpathians, Eastern, Central, and Western Alps; Black Forest, Vosges, Pyrenees, Caucasus, Central and Northern Europe; Altai. British.