Viola rostrata

Copyright: Flora of North America Association

Plants perennial, caulescent, not stoloniferous, 5–20 cm. Stems 1–7, ascending to erect (often declining during anthesis), glabrous, on caudex from fleshy rhizome. Leaves basal and cauline; basal: 1–5; stipules lanceolate, margins laciniate, apex acute; petiole 1–9.6 cm, glabrous; blade sometimes purple-spotted abaxially and/or adaxially, reniform to ovate, 1–4.5 × 1–4 cm, base broadly cordate to cordate, margins crenate to serrate, mostly eciliate, apex obtuse to acute, surfaces usually pubescent, mostly adaxially toward base, sometimes glabrous; cauline similar to basal except: petiole 0.4–4 cm; distal cauline blades ovate to deltate, 1–4.5 × 1–4 cm, base cordate, apex acuminate to acute. Peduncles 5–9 cm, usually glabrous. Flowers: sepals lanceolate, margins eciliate, auricles 1–2 mm; petals pale lavender-violet on both surfaces, all white basally, lower 3 purple-black-veined, all beardless, lowest 8–20 mm, spur white, purple, or lavender-tinged, elongated, 10–20 mm; style head beardless; cleistogamous flowers axillary. Capsules ellipsoid, 4–6 mm, glabrous. Seeds beige to bronze, 1.3–2 mm. 2n = 20.

Phenology: Flowering Apr–May.
Habitat: Rich, mesic to dry, well-drained woodlands, mountains
Elevation: 200–1800 m

Ont., Que., Ala., Conn., Ga., Ind., Ky., Md., Mass., Mich., N.J., N.Y., N.C., Ohio, Pa., S.C., Tenn., Vt., Va., W.Va., Wis., e Asia (Japan)

Discussion

Viola rostrata has the longest spur of any North American Viola species.

Viola rostrata reportedly hybridizes with V. labradorica (= V. ×malteana House) and V. striata (= V. ×brauniae Grover ex Cooperrider).

Selected References

None.

Lower Taxa