Impatiens putaoensis Y.H. Tan, S.S. Zhou & B.Yang, 2017

Yang, Bin, Zhou, Shi-Shun, Maung, Kyaw Win & Tan, Yun-Hong, 2017, Two new species of Impatiens (Balsaminaceae) from Putao, Kachin State, northern Myanmar, Phytotaxa 321 (1), pp. 103-113 : 107-109

2. Impatiens putaoensis Y.H. Tan, S.S. Zhou & B.Yang , sp. nov. ( Figs. 2 (G–I), 3)

Diagnosis:—The new species similar to I. xanthina Comber (1934: 248) , but it can be distinguished from the latter by having light greenish yellow flowers, lateral sepals ovate to elliptic, 1.2–1.6 × 0.7–1.1 cm, lower lobe of united petalssemilunar, 2.6–3.0 × 0.8–1.0 cm, upper lobe of united petals dolabrate, 1.5–1.7 × 1.4–1.6 cm, dorsal petal ovate to nearly orbicular, 1.1–1.4 × 0.7–1.2 cm, dorsally sometimes with a inconspicuous narrow crest.

Type: — MYANMAR. Kachin State: Putao, Ghatu village , 97º51 ʹ 9.47 ʺ E, 27º43 ʹ 28.99 ʺ N, alt. 590 m, 25 Nov. 2014, Myanmar Exped.105 (holotype: HITBC!; isotypes: KUN!, RAF!) .

Terrestrial, perennial herb, 20–40 cm tall. Stem erector ascending from base, succulent, with dense spreading hairs. Leaves alternate, aggregated at stem apex; petiole 1.5–3.5 mm long, densely white or rufous pilose; leaf blade elliptic to broadly elliptic, 6–8 × 3–5 cm, both surfaces sparsely or densely pubescent, base attenuate, apex acute, margin crenate, with spinose teeth. lateral veins 5–8 pairs. Racemes solitary inupper axils, 1–4(–6)-flowered; peduncle 2.5–5 cm long, densely white pilose. Pedicels 1.5–3 cm long, densely white pilose, bracteate at base. Bracts elliptic to narrow-lanceolate or linear, 0.8–1 cm long, sparsely pubescent, apex acute, base obtuse, margin entire. Flowers greenish yellow or creamy, 4.0– 4.5 cm long. Lateral sepals 2, ovate to elliptic, 1.2–1.6 × 0.7–1.1 cm, acute at apex, obtuse at base, sparsely pubescent, greenish yellow. Lower sepal infundibuliform, 2.0–2.2 × 1.4–1.6 cm, outside pubescent, yellow or pale greenish yellow, narrowed into an up-curved hooked spur ca. 3.5 cm long. Dorsal petal ovate to suborbicular, or elliptic, 1.1–1.4 × 0.7–1.2 cm, apex retuse, base rounded, midrib obvious, with an inconspicuous dorsal crest, glabrescent or sparsely pubescent; lateral united petals ca. 4 cm long; the upper petals dolabrate, 1.5–1.7 × 1.4–1.6 cm; the lower petals semilunar, 2.6–3.0 × 0.8–1.0 cm, middle part revolute, oblong-cymbiform, basal auricle inflexed, reniform. Stamens 5; filaments ca. 0.8 cm long, white; anthers yellow. Ovary ca. 0.6–0.8 cm long. Capsule fusiform, ca. 1 cm long.

Phenology: —Flowering from October to November and fruiting from November to the following February.

Distribution and habitat: — Impatiens putaoensis is known from Putao, Kachin State, Myanmar. It grows on wet places understory tropical rain forests, 500– 700 m.

Etymology:— The specific name refer to the type locality.

Affinities:— This new species is similar to Impatiens xanthina , particularly in the elliptic to broadly elliptic leaves and the pubescent stems and pedicels, few-flowered short raceme, but differs in its light greenish yellow flowers (not yellow, with reddish spots); lateral sepals ovate to elliptic, 1.2–1.6 × 0.7–1.1 cm (not ovate, 8–9 × 4–5 mm), lower lobe of united petals semilunar, 2.6–3.0 × 0.8–1.0 cm (not sub-orbicular, ca. 1.5 × 1.1 cm), upper lobe of united petals dolabrate, 1.5–1.7 × 1.4–1.6 cm (not broadly triangular-obovate, ca. 1.2 × 1.2 cm), dorsal petal ovate to nearly orbicular, 1.1–1.4 × 0.7–1.2 cm (not. nearly orbicular, ca. 1.4 × 1.8 cm), dorsally sometimes with a inconspicuous narrow crest (not abaxial midvein conspicuously cristate) ( Table 2, Figs. 2 : G–I, 3).

Additional specimens examined (paratype): — MYANMAR. Kachin State: Putao, Gathu, 97º56 ʹ 41 ʺ E, 27º 28 ʹ 31 ʺ. Understory herbs in tropical rain forests, alt. 613 m, 11 Dec. 2016, Myanmar Exped. 834 (HITBC).

Figures

FIGURE 2. Impatiens casseabriae. A-D. Habit; E. Different parts of the flower and capsule; F. Flower (front view). Impatiens putaoensis. G, H. Habit; I. Different parts of the flower, pedicel with immature capsule and pedicel with flower (lateral view).