Viola rotundifolia |
Viola lithion |
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early yellow or roundleaf yellow violet, round-leaf violet, roundleaf yellow violet, violette à feuilles rondes |
rock violet |
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Habit | Plants perennial, acaulescent, not stoloniferous, 1–20 cm; rhizome thick, fleshy. | Plants perennial, caulescent, not stoloniferous, 5–15 cm. |
Stems | 1–3, ascending to erect, glabrous, on caudex from fleshy rhizome. |
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Leaves | basal, 2–5, prostrate to ascending, often overlapping basally; stipules linear-lanceolate, margins entire, apex acute; petiole 2–8 cm, pubescent; blade unlobed, orbiculate, reniform, or ovate, 2–12 × 1.5–9 cm, base cordate, margins crenate to serrate, sometimes glandular, ciliate or eciliate, apex rounded to acute, surfaces usually pubescent throughout or concentrated proximally on both surfaces. |
basal and cauline; basal: 1–4; stipules unknown; petiole 1–10 cm, glabrous, sometimes finely puberulent; blade broadly ovate or deltate to broadly deltate, 1–2.5(–2.9) × 0.6–2.2(–2.6) cm, base usually cordate to truncate, rarely rounded, margins crenate-dentate, eciliate, apex acute, surfaces glabrous; cauline similar to basal except: stipules lanceolate, margins usually fimbriate-toothed, sometimes entire, apex attenuate or acute; petiole 1.1–3.7 cm, sometimes finely puberulent; blade ovate to deltate, 0.7–2.2 × 0.4–1.2 cm, base sometimes rounded on distal blades. |
Peduncles | 1.5–7 cm, usually pubescent. |
3–6(–10) cm, glabrous. |
Flowers | sepals lanceolate to ovate, margins ciliate or eciliate, auricles 0.5–1 mm; petals deep lemon-yellow on both surfaces, lower 3 brownish purple-veined, lateral 2 bearded, lowest 8–11 mm, spur yellow, gibbous, 1–2 mm; style head beardless; cleistogamous flowers on prostrate or partially subterranean rhizomes or on racemelike, nonrooting, and usually leafless branches growing from rhizome apex. |
sepals lanceolate, margins eciliate, auricles 0.5–1 mm; petals blue to pale violet on both surfaces with yellow area basally, lower 3 purple-veined, lowest with yellow area, lateral 2 bearded, lowest 5.5–11 mm, spur white to pale violet, gibbous, 0.5–1.3 mm; style head bearded; cleistogamous flowers unknown. |
Capsules | ellipsoid, 5–10 mm, glabrous. |
subglobose, ca. 5 mm, glabrous. |
Seeds | beige, 1–2 mm. |
dark brown, ca. 1.8 mm. |
2n | = 12. |
|
Viola rotundifolia |
Viola lithion |
|
Phenology | Flowering Mar–May. | Flowering Jun–Aug. |
Habitat | Rich montane forests and other mesic woodlands | Seasonally wet cracks and crevices, narrow ledges of rock outcrops, shaded northeast-facing avalanche chutes, cirque headwalls, subalpine conifer zone |
Elevation | 200–2000 m (700–6600 ft) | 2300–3100 m (7500–10200 ft) |
Distribution |
CT; DE; GA; KY; MA; MD; ME; NC; NH; NY; OH; PA; RI; SC; TN; VA; VT; WV; ON; QC
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NV; UT |
Discussion | N. H. Russell (1955b) stated that Viola rotundifolia is a primitive member of Viola and probably one of the ancestral species of stemmed yellow violets of North America. Russell (1965) stated that morphologically, V. rotundifolia is one of the most invariable violets and suggested that its nearest relative is V. orbiculata. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Of conservation concern. Viola lithion is known only from the White Pine Range in Nevada and the Pilot Range straddling the Nevada-Utah border. It is related to V. canadensis and V. flettii. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 6, p. 155. | FNA vol. 6, p. 136. |
Parent taxa | Violaceae > Viola | Violaceae > Viola |
Sibling taxa | ||
Name authority | Michaux: Fl. Bor.-Amer. 2: 150. (1803) | N. H. Holmgren & P. K. Holmgren: Brittonia 44: 300, fig. 1A – D. (1992) |
Web links |