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Northern Ontario Plant Database
Plant DescriptionViola blanda Willd.En: sweet white violet, largeleaf white violet, Willdenow's violet, woodland white violet
Violaceae (Violet Family) Click on thumbnail to see larger image.
General: A low, perennial forb, spreading by long thin runners (stolons). See more information on the genus Viola at the end of this webpage. Nomenclatural Notes: In the north, Viola blanda was formerly known as Viola incognita Brainerd. Viola blanda var. palustriformis is the variety known from northern Ontario, but varieties are no longer recognized within Viola blanda (see McKinney & Russell 2002). Leaves: Basal, simple, palmately-veined, long petiolate. Leaf blade ovate to cordate, 3–6 cm long during the flowering period, longer at maturity, 2.5–8 cm wide; leaves very hairy when young, becoming smooth with maturity (glabrate); the basal lobes cordate; early leaves with rounded tips, later leaves with pointed tips; margins with low rounded teeth (crenate). Flowers: Bisexual, white, not very fragrant, 1–1.5 cm long; flower stalk (peduncle) green, hairy. Sepals 5, lanceolate-ovate, acute; petals 5, the 2 lateral petals bearded, lower petal smooth, veined with purple. Flowers blooming in early spring. Fruit: A small ovoid capsule, purplish, smooth (glabrous), 4–6 mm long; seeds buff to greenish brown, 1.9–2.1 mm long. Fruits mature in summer. Habitat and Range: Dry to very moist woods, thickets, clearings. Viola blanda is a temperate eastern North American species typically found in deciduous and mixedwood forests. Similar Species: In addition to the sweet white violet, there are 3 other stemless white violets in northern Ontario. Of these, Viola lanceolata (lanceleaf violet) is easily identified, as it is the only violet with narrow, lanceolate to oblanceolate leaves. The remaining species all have cordate to reniform leaves; Viola macloskeyi (northern white violet) and Viola renifolia (kidneyleaf violet) can be differentiated from the sweet white violet by their smooth, beardless petals. Viola renifolia has hairy leaves and the leaf is usually broader than long, with a rounded apex. It can be found in cedar forests over limestone bedrock, often in association with Calypso bulbosa (fairy slipper orchid), Goodyera oblongifolia (Menzies' rattlesnake plantain), and Goodyera tesselata (checkered rattlesnake plantain). See also Viola renifolia page from borealforest.org. The genus Viola - stemless white species Violaceae – Violet Family The typical violet has basal leaves that are simple and heart-shaped (cordate), but some violets have narrow, lanceolate leaves or divided leaves, and some species have tall or creeping stems that bear leaves along the length of the stem. Leaf margins are typically crenate, with rounded teeth. Flowers are solitary at the end of stalks (peduncles), with 5 green sepals and 5 purple, yellow, or white petals. The lower petal is spurred and often marked by purple veins. The 2 lateral petals may also have a few purple veins. Some or all of the petals may be bearded. The anthers of the 5 stamens surround the style of the pistil. The 3-carpelled ovary develops into a capsule that splits into 3 boat-shaped segments. The smooth seeds are expelled from the matures capsule as the sides of the capsule wall in each segment press together from the base upward, forcibly squeezing the seeds out of the fruit. Violets also bear small, self-pollinating (cleistogamous) flowers, which lack petals and do not open; these flowers fertilize and set fruit while still in bud. There are 14 native species of violets (Viola) in northern Ontario. Although often regarded as a difficult group to identify, many former species have recently been combined, making identification much easier. The most important characters to note when trying to identify violets are: – the number of bearded petals (0–5) – the shape of the beard hairs (straight or swollen at the tips) – the presence or absence of hairs along the margins of the sepals (ciliate or entire) – the length of the spur on the lower petal (short or long spurred) – the presence or absence of hairs on the upper or lower leaf surfaces and flower stalks – the presence or absence of stolons – slender runners that spread just below the surface. Violets can be divided into 4 main groups, based on flower colour and presence or absence of above-ground stems:
A key to the stemless white violets is provided below, followed by a chart that compares the traits of each of the stemless white violet species.
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