Impatiens mogangensis Y.M. Shui & W.H. Chen, 2024

Lyu, Ling, Huang, Qing, Shui, Yu-Min, Zhang, Jin-Guo & Chen, Wen-Hong, 2024, Impatiens mogangensis (Balsaminaceae), a new species from Yunnan, China, Phytotaxa 670 (4), pp. 293-300 : 294-298

Impatiens mogangensis Y.M. Shui & W.H. Chen sp. nov. ( Figs. 1 , 2 )

Type: — CHINA. Yunnan: Wenshan Zhuang and Miao Autonomous Prefecture, Maguan County, Gulinqing Community, Mogang Village , 103°55’10’’E, 22°43’10’’N, elev. 560–587 m, 16 October 2022, in flower, Y.M. Shui M2002-03 (holotype: KUN1602118 ) .

Diagnosis: — Impatiens mogangensis is similar to I. morsei in the white-tipped, yellow and brown-striated flowers, slightly bilobed spurs, obconic capsules, and brick-shaped seeds, but can be distinguished by having mainly 5–7 pairs of lateral veins (vs. 10–12 pairs in I. morsei ), serrate leaf margins (vs. crenulate), and the reflexed falcate lower lobes of the lateral united petals (vs. slightly reflexed broad ovate lower lobes). Besides, I. mogangensis resembles I. bonii in its reflexed lower lobes of lateral united petals, size proportions of the upper-to-lower lobes of their lateral united petals, obconic capsule, and brick-shaped seeds, but can be differentiated by having mainly 5–7 pairs of lateral veins (vs. 3–5 pairs in I. bonii ), serrate leaf margins (vs. sparsely crenate-serrate), dorsal petal with an oblique and obtuse triangular crest (vs. with an oblique and acute triangular crest), and the falcate (vs. narrowly falcate) lower lobes of lateral united petals.

Description

Herb, annual, 30–50 cm tall, stems succulent, glabrous, erect, upwards simple or branched. Leaves alternate, crowded apically; petiole 4–8 cm long, glabrous; leaf blade dark green adaxially, greenish abaxially, oblong, ovate-lanceolate, 6.3–10.5 × 2.1–3.6 cm, with 2 basal glands (extrafloral nectaries), lateral veins 5–7 pairs, rarely 8 or 9 pairs, base decurrent, margin serrate, teeth mucronate, apex acuminate. Peduncle absent. Pedicels 4.4–5.9 cm long, glabrous, bracteate at base. Bracts ca. 2.7 × 1.4 mm, lanceolate, inconspicuous. Flowers axillary, solitary, white, brown striate, with yellowish patches. Lateral sepals 4; outer 2, obliquely orbicular, 8–10 × 6–8 mm, veins 9 pairs, midnerve conspicuous, apex mucronate; inner 2, ovate, ca. 2.1 × 1.3 mm, apex mucronate. Lower sepal obliquely funnelform, 2.1–2.5 cm long, 1.5–1.8 cm wide, 0.6–0.9 cm deep, orange-brown striate, abruptly constricted into an incurved spur, spur slightly bilobed, swollen in the middle, 0.8–1.4 cm long. Dorsal petal broadly elliptic or ovate with the apex strongly reflexed, 1.2–1.4 × 0.7–0.8 cm, brown striate, apex white, retuse, abaxial midvein carinate, dorsally with a green and obtuse triangular crest at midvein, crest ca. 0.7 × 0.2 cm. Lateral united petals 1.9–2.5 cm long, 2-lobed, white, brown striate, with yellowish patches; upper lobe obliquely triangular, yellow, brown, 1.1–1.3 × 0.7–1 cm; lower lobe elongated, falcate flabelliform, acuminate and ribbon-like, white, 1.3–1.5 × 0.3–0.4 cm, margin reflexed. Stamens 5; filaments flattened; anthers obtuse. Ovary fusiform, glabrous, many ovules per locule. Capsule 2.1–3.1 cm long, obconic, fusiform, apex rostriform, glabrous, obviously 4-angled. Seed brick-shaped, 6–8, oblong, ca. 4 × 2 mm, densely covered with spiral-shaped hairs. Flowering and fruiting from August to October.

Phenology: —Flowering and fruiting from August to October.

Etymology: —The epithet refers to the type locality, Mogang Village, Yunnan Province, China. The Chinese name of this new species is given as 磨岗凤仙花 ( Chinese pinyin: mó ɡǎnɡ fènɡ xiān huā).

Habitat & distribution: —This species occurs in damp, shaded areas of stream sides or in dense forests in limestone valleys at elevations of 560– 675 m. It is endemic to Yunnan Province. For now, it is found only in its type locality.

Conservation status: —This species is confined to Maguan County, Yunnan Province, with a population of more than 250 but less than 1000 mature individuals. However, there is not sufficient data available regarding its threats and population size reduction over the years for the time being. According to the IUCN Standards and Petitions Subcommittee ( IUCN 2024), Impatiens mogangensis is preliminarily assessed as Data Deficient (DD).

Additional specimens examined (paratypes): — CHINA. Yunnan: Wenshan Zhuang and Miao Autonomous Prefecture, Maguan County, Gulinqing County, Mogang Village , elev. 675 m, Yu-Min Shui et al. 30810 ( KUN) ; the same locality, 106°56’21’’E, 22°56’36’’N, elev. 675 m, 30 August 2016, Yu-Min Shui s.n. ( KUN) .

Figures

FIGURE 1. Impatiens mogangensis. A. Habit. B. Adaxial and abaxial surface of leaf blade. C. Two basal glands. D. Lanceolate bracts at the base of pedicels. E. Serrate leaf margin. F. Capsules. G. Brick-shaped Seeds. Photos by Ling Lyu (A–B, E–G) and Shi-Wei Guo (C–D, H). Note: Br: bracts, Su: suture.

FIGURE 2. Flower structure of Impatiens mogangensis. A. Flower, front view; B. Flower, lateral view, dorsally with an oblique and obtuse triangular crest on the midvein. C. Inner pair of lateral sepals. D & E. Dissection of flower. F & G. Lateral united petals, to show strongly reflexed and falcate lower lobes. H. Gynoecium and androecium.All photos by Shi-Wei Guo.