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.
The habitat of this plant is woods and copses in the south. The habit is erect, more or less pyramidal. The stem is simple or branched. The leaves are oblong, egg-shaped, heart-shaped, toothed, scalloped, with the scent of Woodruff, stalked or stalkless, the nerves hairy below. The bracts are leaflike. The flowers are creamy-white, with white margin and pink or purple spots or variegated. The corolla-tube is nearly straight, with an oblique mouth and spreading lips. The upper lip of the calyx with 2-3 teeth is open, with short, broad sepals. The nutlets are smooth or netted. The plant is 1-2 ft. high, flowering in May and June, and is a herbaceous perennial.
This plant is found in woods at medium altitudes. The habit is erect. The stem is hairy, glandular above. The leaves are oblong, egg-shaped, heart-shaped below, toothed, the lower ones are scalloped, long-stalked. The leaves on the flowering stems are large, stalkless, mostly toothed. The bracts are linear, lance-shaped, as long as the calyx. The flowers are purple, with white spots, in distant axillary whorls. The corolla much exceeds the calyx, which is hairy externally, the teeth of the latter being broadly and narrowly pointed. The plant is 1-3 ft. in height, flowering in June and July, and is a herbaceous perennial.