VIOLACEAE
Meaning:- Viola (L) The ancient Latin name for a violet.
General description:-
A widespread family including herbs, shrubs, trees and climbers. British wild representatives belong to Viola and are annual, biennial or perennial herbs. They have stipulate leaves and characteristic bilaterally symmetrical flowers with a spurred lower petal. Tropical members of the family may differ markedly in habit and floral symmetry.
Stems:-
1) Habit, leafy and erect or ascending, or reduced to a short rootstock with basal leaves and separate flower stalks.
2) Perennial growth, sometimes spreading by rhizomes or stolons; the presence or absence of runners is important in identifying British Viola.
Leaves:-
1) Basal, sometimes forming a persistent rosette; usually petiolate.
2) Cauline, generally alternate when present;
a) blade, simple, rounded, cordate, ovate or lanceolate in British species.
b) margins, commonly crenate or serrate.
c) surface, glabrous or hairy; hair distribution can help separate related species.
3) Stipules, paired at the leaf bases; entire, toothed, fringed or deeply divided. Their size and the form of the terminal division are important diagnostic characters.
Flowers:-
1) Inflorescence, in British Viola, flowers usually solitary and pedicellate, arising from leaf axils or basal growth.
2) Bracts, 2 small bracteoles generally present on each flower stalk; their position may assist identification.
3) Flowers, normally bisexual and bilaterally symmetrical in Viola; many perennial species also produce small closed, self-pollinating flowers later in the season.
4) Calyx, 5 free, persistent sepals, each with a backward-projecting basal appendage in Viola.
5) Corolla, usually violet, blue, yellow, cream or white, sometimes combining several colours;
a) petals, 5 and free, commonly arranged as 2 upper, 2 lateral and 1 lower.
b) lower petal, prolonged into a nectar-containing spur; often marked with darker veins.
c) lateral petals, sometimes bearded near their bases.
6) Stamens, 5, closely surrounding the ovary;
a) filaments, very short; the lower pair carry nectar-producing appendages extending into the petal spur.
b) anthers, closely appressed, with conspicuous terminal connective appendages.
7) Ovary, superior, usually formed from 3 united carpels, with one chamber and parietal placentation;
a) style, single, often curved or bent.
b) stigma, variously shaped, useful in separating major groups.
Fruit and seeds:-
1) Capsule, the fruit of British Viola, usually opening into 3 valves; drying valves can eject seeds.
2) Seeds, several, often bearing a fleshy appendage that encourages dispersal by ants.
3) Fruiting characters, capsule shape, hairiness and the orientation of its stalk can assist species identification; some tropical family members have fleshy fruits instead.
Recognition:-
In British plants, the combination of stipules, 5 free unequal petals, a spurred lower petal and a superior ovary is characteristic. Reliable species identification uses leaf arrangement, stipules, sepals, spur, hairs and fruit together; flower colour alone is insufficient.
Groups relevant to this batch:-
Pansies: Viola arvensis, Viola lutea and Viola tricolor have conspicuously divided stipules and broad-faced flowers. Other violets in this batch differ particularly in basal-rosette development, runners, leaf shape and spur characters.
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Toxicity:-
Toxicity and traditional uses vary across the family. No general statement of edibility applies to all members; the diagnostic descriptions do not assess ingestion safety.
Habitat:-
British species occupy woodland, hedges, grassland, heath, upland pasture, arable ground, bogs and fens, depending on the species.
Distribution:-
Worldwide. Woody genera are especially diverse in tropical regions; Viola is prominent in temperate regions and mountains. British representatives include native taxa and archaeophytes.
Conservation status:-
Varies by taxon. The 2025 Great Britain assessment lists Viola canina and its typical subspecies, and Viola tricolor subsp. tricolor, as Vulnerable. Viola stagnina, the British fen violet traditionally called Viola persicifolia, is Critically Endangered. The other requested taxa are Least Concern.
Taxonomic note:-
VIOLACEAE belongs to Malpighiales. Hybridisation and differing subspecies treatments complicate identification in Viola; scientific names must be interpreted in the context of the flora being used.
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