Impatiens hambaeksanensis B.U.Oh, 2022

Oh, Ami, Jang, Hyun-Do, Lee, Jung Sim & Oh, Byoung-Un, 2022, Impatiens hambaeksanensis (Balsaminaceae), a new species from South Korea, PhytoKeys 211, pp. 139-150 : 139

Impatiens hambaeksanensis B.U.Oh sp. nov.

Figs 1 , 2 , 3 , 4

Type.

South Korea. Province Gangwon-do : Jeongseon-gun , Gohan-eup, Mt. Hambaeksan, shady valley near stream in mountainous area, 37°09'31.53"N, 128°53'16.90"E, 1171 m, 5 Sep 2021, B.U.Oh & J.O.Kim 210905-001 (holotype: KB!; isotypes: KB!, KE!) (Fig. 1 ) .

Diagnosis.

I. hambaeksanensis is similar to I. furcillata in its overall characteristics, including taproot, alternate phyllotaxis and racemose inflorescence, but different from it in some ways: I. hambaeksanensis has serrate leaf margin with flat tooth tip; inflorescence is erect; flower is smaller and mostly white or rarely pinkish-white; the distal part of the lower sepal is mostly non-coiled or rarely 1-coiled; the spur tip is expanded, round and slightly biparted.

Description.

Herb annual, 42-85 cm tall. Roots taproots. Stems erect, pale green to green or rarely purplish-green, branched, piliferous, with multicellular multiseriate glandular trichomes. Leaves alternate, usually glabrous or having scattered simple trichomes when immature; petioles 2-3.5 cm long; blade green, elliptic or rhomboid-elliptic, 6-11 cm long, 4-6 cm wide, apex acute, base acute or rounded, margin serrate. Bracts triangular, 2.5-4 mm long, 1.5-2 mm wide, glabrous. Inflorescences racemose, axillary; rachises purplish-green, ascending, erect, 4-10 cm long, having dense multicellular multiseriate glandular trichomes; pedicels purplish-white, 0.7-1 cm long, glabrous. Flowers usually white or pinkish-white with yellowish and purplish spots, 2-2.6 cm long, 1.1-1.6 cm wide. Sepals 3; lateral sepals 2, brownish-white, ovate, ca. 6 mm long, 4-5 mm wide; lower sepal 1, white or pinkish-white with yellowish and purplish spots, funnel-form with slender spur, 10-18 mm long, 7-11 mm wide; spur usually not coiled, rarely 1-time coiled, 0.5-0.8 mm long, spur tip expanded, round, slightly biparted. Petals 3; dorsal petal 1, usually white or brownish-white, transversely elliptic, 4.8-5.1 mm long, 5.4-6 mm wide, apex emarginate, base truncate; lateral united petals 2, white or rarely pinkish-white with yellowish and purplish spots, 2-lobed, 9.5-13 mm long; basal lobe white, elliptic, 2.5-4 mm long, 1-2 mm wide; distal lobe white, obovate, 7-11 mm long, 3.8-4.4 mm wide. Stamens 5; filaments linear, upper part connate in a ring around the ovary apex, ca. 3 mm long; anthers white, ovoid, ca. 1 mm long. Pistil 1; ovary fusiform, 2.2-2.4 mm long, glabrous; style very short, ca. 0.5 mm long; stigma 5, beak-like. Fruits capsules, slender, fusiform, 14-18 mm long, glabrous. Seeds 2-5 per capsule, ellipsoidal, brown or dark brown, 4-4.6 mm long, 1.7-2.6 mm wide, surface irregularly reticulate with anticlinal wall. Pollen grains oblong with 4 apertures, 29.4-33.3 µm long, 15.7-21.6 µm wide (Figs 2 - 4 ).

Distribution and habitat.

In South Korea, I. hambaeksanensis is only observed in the central regions, especially in the Baekdudaegan Mountain range, including Gangwon-do (Jeongseon-gun and Yanggu-gun). I. hambaeksanensis is generally found in shady valleys or slopes near streams. In contrast, I. furcillata is distributed in the southern coastal regions of South Korea ( Oh et al. 2016) (Fig. 6 ). This species is recorded from China and Russia, though it is possible that the plants in those regions were falsely identified as I. furcillata , considering their smaller flower which is 0.6-1.8 cm long and the northern limit of I. furcillata in South Korea.

Phenology.

Flowering was observed from July to October. Fruiting was observed from late July to late October.

Conservation status.

Currently, the known habitats of this new species are not legally protected. However, fortunately, many individuals of this species have been detected in the natural populations and the habitats are located in deep mountain valleys. Since the habitats are difficult to access, there may not be problems regarding habitat conservation within the near future. According to the IUCN (2019) Red List Criteria, we suggest that I. hambaeksanensis be treated as Data Deficient (DD).

Additional specimens examined.

(paratypes): South Korea. Gangwon-do : Injae-gun , Mt. Daeamsan , 19 Sep 2021, LJS21091901 (KH!); Jeongseon-gun, Mt. Hambaeksan , 5 Sep 2012, KIMJH12157 (KB!), 2 Sep 2015, Ji S-J et al., sn. (KH!); Pyeongchang-gun, Mt. Gyebangsan , 23 Aug 2012, Nam C-H et al. Gyebangsan-120823-035 (KH!); Taebaek-si, Mt. Taebaeksan, 16 Aug 2012, Byeon J-G et al., sn. (KH!), 10 Sep 2013, Yang J-C et al., sn. (KH!); Yangyang-gun, Mt. Seolaksan, 18 Sep 2018, KIMJH18092 (KB!); Yanggu-gun, Dolsanryong, 17 Sep 2021, B.U.Oh & J.O.Kim 210917-001 (KB!) .

Figures

Figure 1. Holotype of Impatiens hambaeksanensis B. U. Oh, B. U. Oh & J. O. Kim 210905 - 001 (KB).

Figure 2. Morphological characteristics of Impatiens hambaeksanensis A habit B stem C leaf D inflorescence E frontal view of flower F lateral view of flower G fruit H seed. All photos by Byoung-Un Oh.

Figure 3. Flower variation ranges of Impatiens hambaeksanensis A-H lower sepals I-P distal part of lower sepals and spur tips. Scale bars: 5 mm (A-H); 1 mm (I-P).

Figure 4. Reproductive organs and their vasculatures of Impatiens hambaeksanensis (White spots between veins are raphides) A frontal view of flower B lateral view of flower C lateral sepals D lower sepal E dorsal petal F lateral united petals G stamen H pistil. Scale bars: 5 mm (D); 2 mm (C, E, F, G, H).

Figure 6. Geographical distribution of Impatiens hambaeksanensis (●) and I. furcillata (○).