Impatiens haridasanii Hareesh & M.Sabu, 2017

Hareesh, Vadakkoot Sankaran & Sabu, Mamiyil, 2017, Impatiens haridasanii (Balsaminaceae), a new species from Arunachal Pradesh, northeastern India, Phytotaxa 326 (4), pp. 264-268 : 264-266

Impatiens haridasanii Hareesh & M.Sabu sp. nov. ( Figure 1 )

This species is similar to Impatiens fugongensis but differs from the latter in having a glabrous stem, dorsal surface of the petals and lateral sepals with pubescence along the center but otherwise glabrous, ovate or orbicular basal lobes of lateral united petals, spur apex entire, pale yellow and linear capsule; it also differs from I. xanthina in having leaves with white pubescence on both surfaces, yellow flowers lacking a red spot on the mouth and dorsal petals with a sharp needle-like appendage on the back and a linear capsule.

Type:— INDIA. Arunachal Pradesh: Longding district, Near Pongchau, 23 May 2017, M. Sabu & V. S. Hareesh 152657 (holotype CALI!, isotypes ARUN!, CAL!).

Annual herbs, 8–20 cm tall, stem glabrous, yellowish brown. Leaves alternate or spirally arranged at the top, petiolate; lamina 1.8–3.5 × 1.3–2.5 cm, ovate to ovate-elliptic, apex acute to minutely acuminate, base acute to obtuse, densely pubescent with white hairs on both surfaces, green to pale green above and pale yellow beneath; lamina margin serrate, serration apiculate; lateral nerves 5–8 on each side, prominent; petiole 0.5–4 cm long, terete, pubescent, pale green to pale pink. Inflorescence axillary, pedunculate, 2-flowered; bract 4–6 × 0.5–0.75 mm, linear lanceolate, acuminate at apex, pubescent, pale green; peduncle 1.2–1.75 mm long, pubescent, pale green; pedicel 1–1.3 cm long, puberulent to glabrous, pale green; lateral sepal 2, 3.5–4 × 2–2.3 mm, ovate to obliquely-ovate, with deep keel, apex acuminate, glabrous except white long hairs on the keeled portion, transparent with pale green keeled portion; dorsal petal 5–5.5 × 3.5–3.75 mm, galeiform, glabrous, white, sharp hairs along the keeled dorsal surface, yellow; lateral united petals 10– 12 × 4.75–5 mm, 2-lobed; basal lobe 2.75–3 × 1.5–1.8 mm, ovate or orbicular, apex obtuse, yellow; distal lobe 20–22 × 7–8 mm, dolabriform-triangular, apically obtuse, yellow; lower sepal 8–10 × 6.5–7 mm, navicular, glabrous, yellow; spur 7–10 mm long, cylindrical, deeply curved, glabrous, yellow, apex entire, acute. Column c. 3 × c. 2 mm, straight, curved towards the apex; filament c. 2 × 2 mm, glabrous, white; anther c. 1 × c. 1.75 mm, glabrous, yellow. Pistil 3–3.3 × c. 1 mm; ovary ellipsoid, glabrous, pale green. Capsule 4–4.5 × 0.5–0.7 cm long, linear, glabrous, green.

Flowering and Fruiting: —May to June

Etymology: —The specific epithet haridasanii is in honor of Dr. Haridasan, former Scientist of the State Forest Research Institute, Arunachal Pradesh, who had contributed a lot to the taxonomy of northeast India.

Distribution and ecology: — Impatiens haridasanii is known only from Pongchau, Longding District of Arunachal Pradesh, northeastern India. We observed more than 100 individuals along the roadsides in a few localities within a radius of 3 km near Pongchau town. The species was observed in moist rocky open areas in association with Selaginella sp. , Pellionia sp. , Hedychium sp. , etc. Presently there is no evidence for an immediate threat, but the population could be impacted by shifting land use and road construction. Based on the available data, the conservation status is assessed as Data Deficient (DD).

xanthinoides .

Figures

FIGURE 1. Impatiens haridasanii. A&B. Habit. C. Flower front view. D. Inflorescence side view. E. Flower top view. F & G. Lateral sepal adaxial and abaxial view. H & I. Dorsal petal adaxial and abaxial view. J. Lateral united petals. K. Lower sepal with spur. L. Stamen. M. Carpel. N. Capsule. Photos by M. Sabu & V.S. Hareesh.