Impatiens bijieensis X.X. Bai & L.Y. Ren, 2022

Ren, Liu-Yi, Chen, Yi, Yuan, Tao-Hua, Huang, Rong-Xin, Li, Mei-Jun & Bai, Xin-Xiang, 2022, Impatiens bijieensis (Balsaminaceae), a new species from karst plateau in Guizhou, China, PhytoKeys 192, pp. 1-10 : 1

Impatiens bijieensis X.X. Bai & L.Y. Ren sp. nov.

Figs 1 , 2 , 3A-C

Type.

China. Guizhou: Hezhang County, Xingfa Town, Dajiucaiping , 2763 m alt., 29°59'53"N, 104°45'29"E, 20 Aug 2021, X.X. Bai & L.Y. Ren DJCP 20210820 (holotype: GZAC!; isotype: PE!) .

Diagnosis.

Impatiens bijieensis X.X. Bai & L.Y. Ren, sp. nov. is similar to I. pterosepala , I. lasiophyton and I. leptocaulon in plant height, leaf blade shape and flower shape, especially resembling I. lasiophyton in its pilosity and obtuse anther apices, but distinguished by its deep purplish-red flower, linear-lanceolate bract, apex 2-lobed lower sepal and cylindrical capsule.

Description.

Perennial herb, 30-60 cm high, densely pilose. Root-system developed, with adventitious roots on lower stem nodes. Stem fleshy, erect, branched. Leaves simple, alternate, aggregated at stem apex; petiole 0.3-0.8 cm long; leaf blade elliptic, ovate or ovate-lanceolate, 3.5-5 cm × 1.3-1.8 cm, base cuneate, with a pair of conical glands, margin serrulate, apex acuminate, adaxial surface densely pilose, green; abaxial surface pilose along veins, pale green, lateral veins 6-8 pairs. Inflorescences axillary, 2- or 3-flowered. Peduncles 1.5-1.8 cm long, pedicels 0.4-0.8 cm long, slender, bracteate above middle; bract 1, persistent, linear-lanceolate, 0.3-0.5 cm long, abaxial mid-vein thickened, margin membranous, ciliate.

Flowers deep purplish-red, 2.3-2.5 cm long. Lateral sepals 2, ovate, ca. 0.5 cm × 0.2 cm, margin ciliate, mid-vein carinate, apex acuminate or caudate. Lower sepal navicular, ca. 0.5 cm deep (excluding spur), mouth vertical, ca. 0.8 cm wide, narrowed into an incurved, long spur, ca. 2 cm, apex 2-lobed. Dorsal petal reniform, ca. 0.8 cm × 1.5 cm, base truncate or suborbicular, apex concave, abaxial mid-vein carinate, apex acuminate. Lateral united petals sessile, ca. 1.7 cm long, deep purplish-red with whitish-pink base and reddish patches near auricle, 2-lobed; basal lobes ca. 0.4 cm × 0.2 cm, oblong to obovate-oblong; distal lobes ca. 1 cm × 0.6 cm, dolabriform. Stamens 5, filaments linear, anther apices obtuse; ovary 5-carpellate, narrowly fusiform, 0.4-0.5 cm, erect. Capsule fusiform, 1.3-1.8 cm long, apex acuminate, 5-valved, fleshy. Seed ellipsoid, surface with irregular protrusions.

Etymology.

The specific epithet ‘bijieensis’ refers to the type locality where the new species was found, located in Bijie City, northwest Guizhou Province, China. The Chinese name is given as “毕节凤仙花”.

Phenology.

Flowers and fruits from August to October.

Distribution.

Impatiens bijieensis has been observed in Bijie City, Guizhou Province with subpopulations in Hezhang County and Dafang County. We found at Dajiucaiping, Hezhang that the plants grow along the creek on the slopes of gentle hilltops or on the side slope of the ridge, while some were found below the cliffs where water was dripping from streams. At Jiulongshan, Dafang, the population was distributed in evergreen broad-leaved forest margins.

Ecology.

Impatiens bijieensis was collected at elevations of 1915-2800 m. Species of Rubus coreanus Miq. ( Rosaceae ), Elatostema involucratum Franch. et Sav. ( Urticaceae ) and Allium wallichii Kunth ( Liliaceae ) were found to grow in the vicinity of this species.

Conservation status.

This species is currently known only from Bijie City, Guizhou Province, China with two subpopulations. The Extent of Occurrence (EOO) is less than 100 km2 and the known Area of Occupancy (AOO) is less than 15 km2. The conservation status can be evaluated as Vulnerable (VU) D2, based on the IUCN Red List Categories and Criteria ( IUCN 2019). About 150 and 300 individuals were known in the two subpopulations of Hezhang County and Dafang County, both of which are exposed to human disturbance.

Additional specimen examined.

China. Guizhou: Bijie City: Dafang County, Jiulongshan, 27°19'37"N, 105°52'50"E, 1915 m alt., 8 Sep 2021, X.X. Bai et al., JLS 20210908 (GZAC!).

Figures

Figure 1. Impatiens bijieensis A habit B plant C flower in face view D flower in lateral view E leaf adaxial surface (left) and abaxial surface (right) F inflorescence G flower dissected H fruit I ovary J anther K seeds L root. Photos by Xin-Xiang Bai.

Figure 2. Impatiens bijieensis A habit B dorsal petal C lateral sepal D lateral united petal E lower sepal F anther G fruit H flower in face view I flower in lateral view. Drawings by Yi Chen, based on holotype specimen.

Figure 3. Impatiens bijieensis (A-C) A flower in face view B flower in lateral view C flower dissected (Photos by X. X. Bai, in Hezhang County, 20 August 2021). Impatiens lasiophyton (D-F) D flower in face view E flower in lateral view F flower dissected (Photos by X. X. Bai, in Duyun City, 8 July 2021). Impatiens leptocaulon (G-I) G flower in face view H flower in lateral view I flower dissected (Photos by X. X. Bai, in Guiyang City, 22 June 2019).