16. Viola tricolor L. (miniature pansy, Johnny-jump-up, heart’s ease)

Pl. 575 b, c; Map 2707

Plants annual, with a slender, vertical taproot 1–3 mm thick. Stems 10–35 cm long, erect or ascending, often from a spreading base. Leaves alternate and basal, subsessile to long-petiolate, the petiole glabrous. Stipules relatively large and leaflike, free from the petiole, deeply lobed with a fringe of several, long, linear or oblong-lanceolate segments on each side, the terminal segment much longer and broader than lateral ones, with 3 or more pairs of shallow, blunt or rounded teeth along the margins. Leaf blades 0.5–2.5 cm long, unlobed, obspatulate to nearly circular, rounded or angled to a bluntly or sharply pointed tip, narrowly angled to truncate at the base, the margins otherwise with 3 or more pair(s) of blunt or rounded teeth, the surfaces glabrous. Cleistogamous flowers not produced. Flower stalks only slightly overtopping the leaves. Sepals 5–14 mm long, lanceolate, angled to a sharply pointed tip, the margins glabrous, the basal auricles well-developed. Corollas 10–25 mm long, appearing strongly frontally flattened in life, the petals longer than the sepals, yellowish orange to purple on the same flower, the upper petals commonly tinged or tipped with dark blue, the lateral and lower petals often with darker veins or dark purple lines, with a yellow throat (this usually best developed on the lower petal), the lateral petals bearded on the upper surface with mostly knob-shaped hairs, the lowermost petal glabrous on the upper surface, the spur 1–2 mm long, well-exserted beyond the sepal auricles, relatively stout. Stamens not exserted, typically not visible without dissection of the flower. Style enlarged into a globose, hollow stigmatic tip. Fruits 6–10 mm long, broadly ellipsoid, green, drying to tan, the surface glabrous. Seeds 1.5–1.7 mm long, tan. 2n=26. March–May.

Introduced, uncommon and sporadic (native of Europe; escaped sporadically in the northeastern U.S. west to Utah). Lawns and open, disturbed areas.

Miniature pansies are one of the parents (crossed with a series of wild Old World pansies, including V. altaica Ker Gawl. and V. lutea Huds.) of the garden pansies, which are collectively referred to as V. ×wittrockiana Gams and were developed in the early 1800s. The species itself has a long history of cultivation and breeding in Europe, and also was important in folklore and for various medicinal uses. It apparently does not persist long outside of cultivation in North America.