Impatiens nushanensis Z. Wang, P. P. Wu & S. X. Yu 2022, sp. nov.

Impatiens nushanensis Z. Wang, P. P. Wu & S. X. Yu, sp. nov. (Figs. 4–5)

Type:— CHINA. Yunnan Province: Weixi County, Kangpu Township, Shimenguan Pass, 27°36′9.16″N, 99°5′10.98″E, ca. 3276 m a.s.l., 7 August 2019, Zi Wang & Po-Po Wu VTP01017373 (holotype PE!, isotypes PE!).

Description

Herbs, annual, 20–40 cm tall, stems erect, with stipitate glands. Leaves alternate, often aggregated above; petiole 0.8–2 cm long; leaf blades ovate-oblong or elliptic, 3–6 × 1.5–4 cm, membranaceous, adaxially puberulent, with 1–2 stipitate glands at base, base cuneate, oblique, margin crenate, apex acuminate or cuspidate, lateral veins 5–7 pairs. Inflorescences racemose, scorpioid, 2–5 flowered, solitary in leaf axil, peduncle 2–3 cm long, obviously longer than leaves. Bracts borne at the base of pedicel, persistent, ovate to elliptic, 0.4–0.6 × 0.3–0.4 cm, margin entire, apex acute. Flowers light yellow, 3–3.5 cm deep. Lateral sepals 4; outer 2, broadly elliptic or suborbicular, ca. 6 × 4 mm, margin entire, apex mucronulate; inner 2, ovate, ca. 1 × 0.5 mm. Lower sepal obliquely funnelform, 1.5–2 cm long, with deep purple stripes, mouth slightly oblique, distal part abruptly constricted into a straight or curved spur. Upper petal suborbicular, ca. 8 × 7 mm, base truncate, apex rostellate, abaxial midvein carinate. Lateral united petals not clawed, ca. 1.5 cm long, 2-lobed; upper lobe triangular; lower lobe elongated, apex deep purple, acuminate and ribbon-like. Stamens 5, filaments linear, ca. 0.4 cm long. Ovary 5–6 mm long, erect, glabrous. Capsule erect, purplish red, linear, 2–3 cm long. Seed ellipsoid.

Etymology:— The epithet nushanensis refers to the type locality, Nushan Mountain, and the Chinese name of this new species is given as 怒Ɯ凤Njffi.

Phenology:— Flowering from July to August and fruiting from August to October.

Ecology and distribution:— Impatiens nushanensis occurs in shady areas on mountain slope in open fragmented coniferous forests at elevations of 3200–3300 m. It is endemic to Yunnan Province. For now, it is found only in the type locality.

Conservation status:— Only three populations composed of about 400 individuals in total are found. The habitat area is less than 10 km 2, but the microhabitat and microclimate nearby are highly similar. For the time being, the habitat is beyond the interference of human activities, and the populations are without a decline trend. Thus, we propose to categorize the species as Vulnerable (VU D2), following the International Union for Conservation of Nature and Natural Resources guidelines (IUCN Standards and Petitions Subcommittee, 2022).