This section is from the book "British Wild Flowers In The Four Seasons", by Thomas Moore. Also available from Amazon: British Wild Flowers.
L. amplexicaule: annual; stem dwarf, decumbent; leaves roundish-cordate, obtuse, inciso-crenate, the lower ones stalked, the upper sessile, clasping; flowers in 1-3 compact semi-whorls, the corolla purple, its tube slender, much longer than the softly hairy calyx; lateral lobes of the lower lip of the corolla toothless. - Henbit Nettle. - Waste and cultivated ground. Fl. May to September.
L. purpureum: annual, with low spreading stems; leaves cordate-obtuse, crenate-serrate, stalked, the upper ones crowded, shortly-stalked, ovate; flowers pale purple, the lip spotted with red, the lateral lobes of the lower lip of the corolla with two teeth. - Red Dead-nettle. - Waste and cultivated ground. Fl. May to September.
 
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