7-9月
The flowers are purple or purplish-red, with a corolla tube extending slightly beyond the calyx, lips 3-lobed with the middle lobe inverted-heart shaped and side lobes ovate-triangular.
Var. erythrophylla often has larger leaves mostly basal, usually pinnate compound with 1-2 pairs of leaflets, occasionally simple, with serrate margins. The undersides are purple and both surfaces are sparsely to nearly hairless.