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Howell's violet, violette de Howell

prostrate blue violet

Habit Plants perennial, caulescent, not stoloniferous, 2–44 cm. Plants perennial, caulescent, stoloniferous, 5–19 cm; stolons green or reddish, leafy, sometimes rooting at nodes, becoming lignified in age.
Stems

1–4, ascending to erect (sometimes later reclining to nearly prostrate), glabrous or sparsely pubescent, on caudex from subligneous rhizome.

1–5, prostrate, spreading, finely puberulent, from current and/or previous year’s growth, on usually vertical, fleshy rhizome, rooting and forming rosettes at or near tip; rooted rosettes often develop into an erect, fleshy caudex from which new stems are produced.

Leaves

basal and cauline;

basal: 1–6;

stipules linear-lanceolate to oblong, margins mostly entire or laciniate with gland-tipped projections, apex acute to acuminate;

petiole 4–15 cm, glabrous or sparsely puberulent;

blade ovate to reniform, 1.9–6.8 × 2.1–6.4 cm, thin, base cordate, margins crenate, ciliate, apex acute to usually obtuse, surfaces glabrous or sparsely puberulent;

cauline similar to basal except: stipules linear-lanceolate or deltate to oblong, apex acute or long-acuminate;

petiole 1–4.5 cm;

blade 2–5.1 × 1.2–5.8 cm.

basal and cauline;

basal: 3–6;

stipules lanceolate, margins laciniate, projections often long-filamentous, apex long-acuminate;

petiole 2.3–7.3 cm, glabrous or pubescent;

blade often purple-spotted abaxially and/or adaxially, ovate to reniform, 1.2–5 × 1.6–3.6 cm, base deeply to broadly cordate, margins crenulate to serrate, ciliate or eciliate, apex rounded to obtuse, surfaces glabrous or pubescent;

cauline similar to basal except: stipules ovate to lanceolate, margins laciniate;

petiole 1–3.5 cm;

blade 1.3–2.9 × 1.4–3.2 cm.

Peduncles

2.8–17.8 cm, glabrous or sparsely pubescent.

5–9.6 cm, glabrous or pubescent.

Flowers

sepals lanceolate, margins ciliate or eciliate, auricles 1–2 mm;

petals violet to soft blue-violet on both surfaces, whitish basally, lower 3 dark violet-veined, lateral 2 densely bearded, lowest 14–23 mm, spur blue-violet to whitish, gibbous to elongated, 2.4–5 mm, usually less than 1/2 lowest petal, tip straight;

style head bearded; cleistogamous flowers axillary.

sepals lanceolate to ovate, margins mostly eciliate, auricles 0.5–1 mm;

petals pale to bluish violet on both surfaces, lower 3 white basally and darker violet-veined, lateral 2 and often upper 2 and lowest bearded, lowest 15–18 mm, spur white, gibbous to usually elongated, 3–5 mm;

style head bearded; cleistogamous flowers axillary.

Capsules

ellipsoid, 7–11 mm, glabrous.

ovoid to ellipsoid, 5–7 mm, glabrous.

Seeds

light brown, 2.1–2.8 mm.

brown, 1–1.5 mm.

2n

= 40, 80.

= 20.

Viola howellii

Viola walteri

Phenology Flowering Apr–Jul.
Habitat Moist, shady areas, coniferous forests, prairies, along streams
Elevation 50–1500 m (200–4900 ft)
Distribution
from FNA
CA; OR; WA; BC
[WildflowerSearch map]
[BONAP county map]
from FNA
AL; AR; FL; GA; KY; LA; MD; MS; NC; OH; PA; SC; TN; TX; VA; WV
[WildflowerSearch map]
[BONAP county map]
Discussion

Viola howellii is similar to V. adunca and usually occupies moister habitats along the western side of the Cascade Mountains (H. E. Ballard 1992). The first documented record of this species in California was recently reported from Siskiyou County (R. J. Little 2010).

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Varieties 2 (2 in the flora).

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Key
1. Leaf blades pubescent, hairs scattered throughout or concentrated along veins, adaxial surfaces, or toward margins; stipule margin processes 1/2+ stipule length.
var. walteri
1. Leaf blades glabrous or pubescent, hairs usually confined to adaxial surfaces; stipule margin processes to 1/2 stipule length.
var. appalachiensis
Source FNA vol. 6, p. 134. FNA vol. 6, p. 163.
Parent taxa Violaceae > Viola Violaceae > Viola
Sibling taxa
V. adunca, V. affinis, V. arvensis, V. bakeri, V. beckwithii, V. bicolor, V. biflora, V. blanda, V. brittoniana, V. canadensis, V. canina, V. charlestonensis, V. clauseniana, V. cucullata, V. cuneata, V. douglasii, V. egglestonii, V. epipsila, V. flettii, V. frank-smithii, V. glabella, V. guadalupensis, V. hallii, V. hastata, V. hirsutula, V. japonica, V. labradorica, V. lanceolata, V. langsdorffii, V. lithion, V. lobata, V. macloskeyi, V. missouriensis, V. nephrophylla, V. novae-angliae, V. nuttallii, V. ocellata, V. odorata, V. orbiculata, V. palmata, V. palustris, V. pedata, V. pedatifida, V. pedunculata, V. pinetorum, V. praemorsa, V. primulifolia, V. prionantha, V. pubescens, V. purpurea, V. quercetorum, V. renifolia, V. riviniana, V. rostrata, V. rotundifolia, V. sagittata, V. selkirkii, V. sempervirens, V. septemloba, V. sheltonii, V. sororia, V. striata, V. subsinuata, V. tomentosa, V. tricolor, V. trinervata, V. tripartita, V. umbraticola, V. utahensis, V. vallicola, V. villosa, V. walteri
V. adunca, V. affinis, V. arvensis, V. bakeri, V. beckwithii, V. bicolor, V. biflora, V. blanda, V. brittoniana, V. canadensis, V. canina, V. charlestonensis, V. clauseniana, V. cucullata, V. cuneata, V. douglasii, V. egglestonii, V. epipsila, V. flettii, V. frank-smithii, V. glabella, V. guadalupensis, V. hallii, V. hastata, V. hirsutula, V. howellii, V. japonica, V. labradorica, V. lanceolata, V. langsdorffii, V. lithion, V. lobata, V. macloskeyi, V. missouriensis, V. nephrophylla, V. novae-angliae, V. nuttallii, V. ocellata, V. odorata, V. orbiculata, V. palmata, V. palustris, V. pedata, V. pedatifida, V. pedunculata, V. pinetorum, V. praemorsa, V. primulifolia, V. prionantha, V. pubescens, V. purpurea, V. quercetorum, V. renifolia, V. riviniana, V. rostrata, V. rotundifolia, V. sagittata, V. selkirkii, V. sempervirens, V. septemloba, V. sheltonii, V. sororia, V. striata, V. subsinuata, V. tomentosa, V. tricolor, V. trinervata, V. tripartita, V. umbraticola, V. utahensis, V. vallicola, V. villosa
Subordinate taxa
V. walteri var. appalachiensis, V. walteri var. walteri
Name authority A. Gray: Proc. Amer. Acad. Arts 22: 308. (1887) House: Torreya 6: 172. (1906)
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