Impatiens damingensis S. X. Yu, C. Y. Xia & H. P. Deng, 2019

Xia, Chang-Ying, Gadagkar, Sudhindra R., Li, Jin, Deng, Hong-Ping & Yu, Sheng-Xiang, 2019, Impatiens damingensis (Balsaminaceae), a new species from Guangxi, China, Phytotaxa 399 (3), pp. 239-247 : 240-242

Impatiens damingensis S. X. Yu, C. Y. Xia & H. P. Deng , sp. nov. Figs. 1 , 2

Type. China. Guangxi: Wuming, Damingshan ; shade and damp places, Alt. 1220m, 2004-09-02, S. X. Yu 3227 (Holotype, PE; Isotype, IBK), same place, 2002-07-09, Y-G Wei 0205 ( IBK) .

Diagnosis. Similar to I. aquatilis Hook.f. in having racemose inflorescences, two lateral sepals and ellipsoid seeds, but is different by way of having ovate or ovate-lanceolate blades, acute apices of bracts, mucronulate apices of lateral sepals, and a slender and slightly incurved spur. SEM results also reveal distinct differences in seedcoat and pollen grain micro-morphology when compared to I. aquatilis .

Annual herb, 25–50 cm tall, glabrous, stems fleshy, erect or ascendant, well branched, basal nodes swollen with adventitious roots. Leaves alternate, often aggregated above, blades 2–4 (–6) cm long, 1.5–2.5 cm wide, ovate or ovate-lanceolate, apex acuminate, margin deep crenate, fimbriated towards the base, base attenuate, petiole 0.5–1.5 cm long, base with 2 petiole glands, midvein obvious beneath, lateral veins 4–6 pairs, arcuate, deep green above, pale green beneath. Inflorescences racemose, 5–9 flowered, solitary in leaf axil, peduncle 5–8 cm long, glabrous, obviously longer than leaves. Flowers 4–4.5 cm long expanded, rose color. Bracts 3–4 mm long, membranous, ovate-elliptic, acuminate, persistent. Pedicels 10–15 mm long, slender. Sepals 3, lateral sepals 2, 4–5 mm long, 2–2.5 mm wide, oblique ovate, inequilateral, apex apiculate. Lip (lower sepal) 10–15 mm long, caliciform or infundibuliform, oral area slightly oblique above, constricted into a 3–3.5 mm long, curved, apex bifid, filiform spur. Standard (dorsal petal) 7–8 mm long, 11–12 mm wide, base truncate, oblong, dorsally with a narrowcrest terminating, beak-like. Alae (united lateral petals) sessile, 2–2.3 mm long, bilobated, base lobe 7–9 mm long, oblong; distal lobe 1.2–1.5 mm long, slightly concave. Stamens 5, filament linear, 2–3 mm long, anther obtuse at apex, Ovary glabrous, erect. Fruit 1.7–1.8 mm long, coryneform, apex beaked, polyspermy. Seeds obovoid, brown, 2.0× 1.3 mm, L/W = 1.54, seed coat tuberculate ( Fig. 3 :A). Fl. Jul.–Sep., Fr. Aug.–Oct.

Figures

FIGURE 1. Impatiens damingensis S. X. Yu, C. Y. Xia & H. P. Deng. A. plant; B. bract; C. lateral sepal; D. vexillum; E. wings; F. labellum; G. filaments and anthers; H. ovary; I. capsule. Drawn by Y. B. Sun from S. X. Yu 3227.

FIGURE 2. A–F: Impatiens damingensis S. X. Yu, C. Y. Xia & H. P. Deng.A. Habitat; B. plants; C. flower, lateral view; D. flower, front view; E. flower and capsule; F. flower branch. G–I: Impatiens aquatilis Hook. f. G. plants; H: flower, lateral view; I: flower, front view.

FIGURE 3. A–C, G–H: Impatiens damingensis S. X. Yu, C. Y. Xia & H. P. Deng. A–C. SEM images of seeds. A. whole view; B. partial view; C. partial view; G–H. SEM images of pollen grains. G. polar view; H. partial view. D–F, I–J: Impatiens aquatilis Hook.f. D–F. SEM images of seeds: D. whole view; E. partial view; F. partial view; I–J. SEM images of pollen grains: I. polar view; J. partial view.