Herbs, annual or perennial, often suffruticose, rarely shrubby; rhizomes present or absent; stem mostly present. Leaves alternate, entire to pinnatisect, ovate-triangular or reniform, cordate, serrate or crenate; petioles sometimes winged; stipules persistent, free or adnate to petiole, lanceolate-ovate, entire, dentate or fimbriate. Flowers irregular, 1 - 2 on long axillary bibracteolate, non-articulate peduncles, often dimorphic with normal and cleistogamous flowers. Sepals persistent. Petals erect or spreading, flat, subequal; lateral ones larger than others; lowermost spurred. Anthers 2-loculed, subsessile, connivent around ovary, each tipped with a small triangular appendage; connectives of lower 2 often produced into spurs within the spur of corolla. Ovary sessile; style much-variable, straight or curved, often geniculate at base, filiform to clavate; stigma variable, truncate or obtuse, lobed or triangular, straight or beaked (Fig. 67). Fruit 3-valved loculicldal capsule; seeds rounded-ovoid, shiny.
Cosmopolitan, distributed chiefly in the temperate regions throughout the world;
ca 500 species, 35 species in India, distributed mostly in the northern temperate and
alpine areas; a few are confined to the lower hills.
Literature.
CHATTERJEE, A. & A. K. SHARMA (1973) Cytological studies on Indian representatives of the genus Viola. J. Genet. 61: 52 - 63. HARA, H. (1975) Viola. In: H. Ohashi, Fl. East. Himalaya (Third Report): 82 - 85.
Notes.
Pollen grains spheroidal, furrow generally three, occasionally 4 to 6, long tapering to pointed ends; furrow membrane smooth, easily ruptured; germ-pore circular or more or less irregular. Exine nearly or quite smooth. (Wodehouse, R.P. in Pollen Grains, New York 442 - 444. 1959).
KEY TO THE SPECIES
| 1a. Stipules pinnatifid or palmatifid; lateral petals directed towards the top of the flower; style expanded
and globose at top
|
33.
Viola tricolor
|
| b. Stipules entire to long fimbriate; lateral petals spreading horizontally; style not globose at top
|
2
|
| 2a. Stigma without beak, with 2 laterally patent lobes
|
3
|
| b. Stigma beaked, triangular marginate, truncate or subtruncate
|
6
|
| 3a. Leaves reniform to rotundate
|
4
|
| b. Leaves ovate-lanceolate
|
5
|
| 4a. Sepals linear-oblong, obtuse; spur ca 2 mm long
|
2.
Viola biflora
|
| 6a. Plants without superterranean stems or stolons; stipules more or less adnate to petioles
|
7
|
| b. Plants with superterranean, decumbent or ascending stems or stolons; stipules free from petioles
|
14
|
| 7a. Leaves deltoid or deltoid-ovate, rather acute, usually with a truncate or shallowly cordate base and
widely divergent basal lobes
|
8
|
| b. Leaves ovate-oblong to orbicular, often rounded at apex, deeply cordate at base with a little divergent
or subconverging basal lobes
|
10
|
| b. Flowers up to 15 mm across
|
9
|
| 9a. Calycine appendages up to 5 mm long, incised, often 1/2 as long as sepals
|
14.
Viola inconspicua
|
| b. Calycine appendages up to 2 mm long, rounded, nearly 1/3 as long as sepals
|
1.
Viola betonicifolia
|
| b. Sepals ovate, ovate-lanceolate,obtuse
|
11
|
| b. Capsules ca 10 mm long
|
12
|
| b. Lateral petals not bearded at base
|
13
|
| 14a. Stipules entire or with a few short teeth; top of style with 2 laterally patent lobes
|
15
|
| b. Stipules with long acute teeth or fimbriate; top of style without laterally patent lobes
|
18
|
| 15a. Leaves cordate-reniform; petioles not or scarcely winged
|
16
|
| b. Leaves elliptic-ovate to oblanceolate; petioles conspicuously winged
|
17
|
| 18a. Leaves ovate-orbicular, weakly cordate at base
|
19
|
| b. Leaves ovate-oblong, deeply cordate at base
|
24
|
| 19a. Peduncles bibracteolate at or below the middle
|
20
|
| b. Peduncles bibracteolate above the middle
|
21
|
| 21a. Spur 3 - 5 mm long
|
22
|
| b. Stipules more or less lobed at apex with a few lateral narrow teeth
|
28.
Viola rupestris
|
| b. Leaves not silvery white beneath; veins not raised below
|
12.
Viola hookeri
|
| 24a. Flowers up to 1 cm in diam.; stipules foliaceous, up to 3.5 cm long
|
17.
Viola jordanii
|
| b. Flowers up to 2 cm in diam.; stipules membranous up to 1.5 cm long
|
25
|
| 25a. Style not thickened upwards, decurved
|
26
|
| b. Style thickened upwards, erect
|
27
|
| 27a. Peduncles bibracteolate at or below the middle
|
28
|
| b. Peduncles bibracteolate above the middle
|
31
|
| b. Leaves pilose or glabrous, acute or prolonged acuminate
|
30
|
| 30a. Leaves deeply cordate at base; spur ca 5 mm long
|
24.
Viola pilosa
|
| 31a. Spur 3ยท5 mm long
|
32
|
| b. Spur up to 2 mm long
|
33
|
| b. Lateral petals not bearded at base
|
34
|
| 34a. Petioles more than twice as long as lamina
|
13.
Viola hossei
|
