Viola barhalensis Knoche & Marcussen, 2016

Knoche, Gerd & Marcussen, Thomas, 2016, Viola barhalensis (Violaceae), a new species from northeastern Turkey, Phytotaxa 275 (1), pp. 14-22 : 14-17

Viola barhalensis Knoche & Marcussen , sp. nov. ( Fig. 1 , 2 )

Holotype:— TURKEY. A8 , Eastern Black Sea Region, Artvin Province: southern slope of the Kaçkar Mountains, Barhal River Valley , along road from Barhal / Altıparmak to Yaylalar , 1700 m, 40°51’58.51”N 41°19’13.65”E, 06 May 2014, G. Knoche K 14 /9 (holotype W!).

Diagnosis: Viola barhalensis is similar to V. sandrasea Melchior , but differs in having leaves puberulent with 0.2 mm hairs (hairs longer or absent in V. sandrasea ) with a subcordate (cuneate in V. sandrasea ) base, strikingly long petioles in relation to the blades, broadly ovate to lanceolate stipules (ovate-lanceolate to linear in V. sandrasea ) and narrowly ovate sepals (oblong-lanceolate in V. sandrasea ).

Acaulous perennial herb, up to 17 cm high at flowering, lacking stolons. Plant puberulent with very short (0.2 mm) hairs on vegetative parts, distinctly reddish purple in all parts in early spring. Rhizome woody, 3–5 mm thick, more or less branched, clothed with remains of petioles. Stipules free, ovate to lanceolate, 8–10 mm × 2–3 mm, membraneous, whitish or purplish tinged, margin long glandular-fimbriate, ciliate in upper third, sometimes trifid at apex. Petioles 25–120 mm, usually very long in proportion to lamina length (3:1), narrowly winged, puberulent above. Leaf blades glossy bluish-green with marked venation, 17–37 mm × 15–18 mm, triangular-ovate or lanceolate, puberulent on both surfaces; base subcordate, apex acute to acuminate; margin serrate-crenate, sometimes undulate, mature leaves with 18–22 crenations. Peduncles of chasmogamous flowers 60–70 mm long, bibracteolate above middle, glabrous except for scattered hairs above; peduncles of cleistogamous flowers 4.5–20 mm. Flowers fragrant, 10 mm long including spur, rectangular in transverse view. Corolla bluish violet with white throat. Sepals narrowly ovate, 6 mm × 2 mm including appendices, purplish tinged, margin hyaline and very sparsely ciliate, apex acute, appendix short, truncate to rounded. Petals obovate, 8–10 mm × 4–6 mm, broad and overlapping, all beardless; lower petal with dark purple veins, spurred; spur 4.5 mm, curved upwards, bluish violet. Style clavate, geniculate at base, apex curved downwards, shortly beaked, epapillous. Cleistogamous flowers ca 4 mm. Capsule globose or narrowly ovate, 7–8 mm in diameter, glabrous with purplish spots, inexplosive, borne on peduncles procumbent at maturity. Seeds 3.1 mm × 1.5 mm, elliptical, cream-coloured, with conspicuous whitish elaiosome.

Phenology:—Chasmogamous flowering in late April to early May, followed by cleistogamous flowerering throughout the rest of the growing season. Fruiting from the beginning of May (in Turkey) to September/October (cultivated plants).

Distribution and habitat:— Viola barhalensis is known only from a small area on the southern slopes of the Kaçkar Mountains, in the Barhal River Valley, Artvin Province, Eastern Black Sea Region, Turkey (A8), 40°58’18.34”N – 40°51’58.51”N, 41°28’43.28”E – 41°19’13.65”E. It is found there along the road from Sarıgöl to Barhal/Altıparmak and Yaylalar, growing in shady crevices of east-facing igneous rocks close to the Barhal river, at 1200–1700 m elevation. This area is situated in the montane zone with all year round precipitation and a humid microclimate due to the proximity to the river. Accompanying chasmophytes are Asplenium septentrionale , Campanula betulifolia , and Saxifraga cartilaginea .

Conservation status:— Viola barhalensis is known only from 10–15 sites close to the village of Barhal and between Barhal and Yaylalar. The area is steep and not easy of access, so only the area along the dirt road along the main valley was checked, and not any side valleys. The species is without question rare and occurs as a small number of individuals and thus should be considered as critically endangered (CR) according to the IUCN Red List criteria (B2a; IUCN 2012).

Etymology:—Named after the village of Barhal, situated close to the type location.

Paratypes:— TURKEY.A8, Eastern Black Sea Region, Artvin Province: southern slope of the Kaçkar Mountains, Barhal River Valley,along road from Sarıgöl to Barhal/Altıparmak and Yaylalar, 1700 m, 40°51’58.51”N 41°19’13.65”E, 06 May 2014, G. Knoche K 14/10 (O!), G. Knoche K 14/11 (HUB).

Figures

FIGURE 1. Viola barhalensis Knoche & Marcussen. A. Habit of flowering plant, drawn from the holotype. B. Stipules.C. Chasmogamous flower, profile view. D. Chasmogamous flower, frontal view. E. Margin of leaf grown in cultivation, showing crenulae and puberulence. F. Stigma, profile view. G. Unripe capsule of chasmogamous flower. H. Ripe seed with elaiosome. Drawings © Thomas Marcussen, reproduced with permission.

FIGURE 2. Viola barhalensis Knoche & Marcussen. A. Barhal valley with upper Kaçkar mountains at a distance, 2 May 2007. B–D. Habitat of V. barhalensis in igneous rock crevices and among stones. E–F. Chasmogamous flowers of cultivated plants. E. Front view. F. Side view. G. Unripe capsule from chasmogamous flower. H. Ripe seeds. Photos © Gerd Knoche, reproduced with permission.