Wednesday, May 16, 2012

How to Identify the White Violets of the Mid Atlantic Region

I have received many requests asking that I continue with the identification of the rest of the violets of the Mid Atlantic.  I had to choose between the nine species of white violet or the 34 species of blue violet.  I chose the easy way out and decided to continue with a post on how to identify the white violets of the Mid Atlantic region.

One of the first identification points to look for when identifying violets is to see whether the plant is stemmed or unstemmed.  Stemmed means that the flower and leaves share the same stem.  Unstemmed means that the flower and leaves have their own individual stems.  Of the nine white violets that grow in our region only two species are stemmed.

Viola canadensis (Canadian White Violet)

Photo: Viola canadensis, Gravitywave

Viola canadensis is a stemmed violet that is very easy to identify.  It is one of the taller violets, ranging in size from 6 -14".  The yellow center of the flower is diagnostic as is the purplish coloration on the back of the top petals.

Photo: Viola canadensis, Jim Brighton

Viola canadensis is absent from the coastal plain but can be found in the piedmont and mountains of all the states in the Mid Atlantic region.  It is endangered in New Jersey.

USDA state map for Viola canadensis

Photo: Viola canadensis, Kent McFarland

Viola striata (Striped Cream Violet)

Viola striata is our other stemmed white violet.  It is easy to identify because the flowers are heavily bearded and do not have yellow centers or purplish backs to the top petals.

Photo: Viola striata, Jim Brighton

Viola striata is very uncommon on the coastal plain and becomes more common in the piedmont and mountains throughout the Mid Atlantic region.

USDA state map of Viola striata

The remaining species of violets are unstemmed.  We will start out with the two toughest species to identify Viola blanda and Viola macloskeyi.  These violets are very similar with only slight differences.

Viola blanda (Sweet White Violet)

Photo: Viola blanda, Stan Lockwood

Viola blanda is a small unstemmed violet that grows in rich woodlands throughout the Mid Atlantic.  The small white flowers typically have the top two petals reflexed and twisted.  

Photo: Viola blanda, Squamatologist

Another important identification point is that the stem of Viola blanda is usually reddish.  The leaves of Viola blanda are cordate.  Cordate means heart-shaped unlike the leaves of Viola macloskeyi which are more ovate to orbicular. Ovate means shaped like an egg and orbicular means very rounded.  

USDA state map for Viola blanda.

Viola blanda can be found sporadically on the coastal plain and becomes more common in the piedmont and mountains throughout the Mid Atlantic.

Viola macloskeyi (Northern White Violet)

As stated above, Viola macloskeyi and Viola blanda are very similar.  Viola macloskeyi is very small, unstemmed, and typically grows in wetter environments than Viola blanda. It is a violet of bog edges and the website Northern Ontario Flora states that this violet especially likes to grow in wet alder thickets.

Photo: Viola macloskeyi, Tom Palmer

Unlike Viola blanda, the stems of Viola macloskeyi are mostly green but they can have red hints.  The upper flower petals of Viola macloskeyi are not twisted but can be reflexed.  The leaves of Viola macloskeyi are more ovate/orbicular than cordate, meaning the leaves are more egg-shaped/circular than heart-shaped.

Photo: Viola macloskeyi, Tom Palmer

Viola macloskeyi is found throughout the Mid Atlantic region.  In North Carolina and Virginia it is restricted to the mountainous regions.  North of the Mason Dixon Line it can be found from the coastal plain through to the mountains.

USDA state map of Viola macloskeyi

Viola renifolia (Kidney-leaved Violet)

Viola renifolia is another small unstemmed violet that is very similar to the previous two species. But, Viola renifolia has one characteristic that sets it apart.  It has hairy leaves. Sometimes only the underside of the leaf is hairy.

Photo: Viola renifolia, Cindy Kilpatrick

In the Mid Atlantic region Viola renifolia is only found in Pennsylvania and New York.  The USDA website lists this violet as extirpated in Pennsylvania, but on the PA Natural Heritage website they list the violet as endangered.

USDA state map for Viola renifolia

Viola lanceolata (Lance-leaved Violet, Bog White Violet)

Photo: Viola lanceolata, Corey Raimond

Viola lanceolata is really easy to identify.  The leaf shape, long and narrow, is a diagnostic feature that easily separates this species from all the other white violets in our region.

Photo: Viola lanceolata, Andy Firk

This plant is always found growing in wet areas such as bogs and ditch edges.  It is most common on the coastal plain, but can also be found in the piedmont and mountains from Virginia north into New England.

USDA state map for Viola lanceolata

Viola x primulifolia (Primrose-leaved Violet)

Photo: Viola x primulifolia, Anita363

The Primrosed-leaved Violet is a common hybrid of Viola lanceolata x Viola macloskeyi.  It is often found in the same habitats as Viola lanceolata.  The distinguishing characteristic of the hybrid are the shape of the leaves.  The leaves are always longer than wide and typically narrowly egg-shaped with a wedge-shaped (cuneate) base.  This leaf shape is diagnostic and will easily differentiate this hybrid from the other white violets.

Photo: Viola x primulifolia, Patrick Coin

Viola x primulifolia is found throughout the Mid Atlantic from the coastal plain to the mountains.

USDA state map of Viola x primulifolia

The last two species of violets are typically not white but have white forms that are occasionally found.

Viola sororia abliflora (White form of Common Blue Violet)

Photo: Viola sororia albiflora, Frank Mayfield

The white form of the Common Blue Violet is occasionally found among the more common blue forms of the flower.  This violet can easily be differentiated from all the other white violet by looking at the small spur in back of the flower (shown in the photo below).

Photo: Viola sororia, Amadej Trnkoczy

As you can see in the photo, the spurs of the violet are reddish green.  The spur is the reddish rounded part of the above flowers.  In all the other white violets the spur is white or whitish yellow.  Viola sororia is found throughout the Mid Atlantic and is one of our most common violets.

USDA state map of Viola sororia

Viola pedata form alba (Bird's-foot Violet)

Viola pedata is another violet that can come in many different colors including pure white.  It is a large violet often found in dry areas where other violets do not typically grow.

Photo: Viola pedata, Peter Gorman

The leaves of this violet easily differentiate it from all the other white violet species.  The leaves are typically divided into four or more lobes and resemble a bird's foot.  This violet is found from North Carolina through to Pennsylvania.  In New York it is very rare with only a few populations.

USDA state map of Viola pedata

I would like to thank all the photographers who made this post possible. Please go to their websites and check out all their cool photos.

The USDA website where I procured the maps for this post can be found here.

The BONAP website was also used to glean geographic information for each of the species in the post.

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