1、 Leaves

The leaves of Huoxuedan are herbaceous, heart-shaped or kidney-shaped, and the length of petiole can reach one or two times that of leaves, often with purple below; The leaves of zihuadiding are triangular or slender oval, the upper part is generally oblong, the length of petiole can reach one or two times that of leaves, and the lower part is often purple

The lower part of the leaf is triangular ovate or narrow ovate, and the upper part is longer, which is oblong, narrow ovate, lanceolate or oblong ovate

2、 Flowers

The flowers of Huoxuedan are relatively few, usually two, rarely 4-6. The bracts are very small, only 4 mm. The calyx is a tubular mechanism, the disc is in the shape of a cup, and the style is slightly extended

The flowers of Viola latifolia are medium-sized, violet or lavender, rarely white, generally light in color and with purple columnar lines