Impatiens marroninus Utami, 2020

Impatiens marroninus Utami , sp. nov. — Fig. 1a–b View Fig , 2 View Fig

Etymology. The species epithet refers to the colour of the peduncles, which is maroon.

Impatiens marroninus is similar in morphology to I. beccarii Hook.f. ex Dunn. In I. marroninus the leaf is dark green; lower sepal deeply navicular, constricted into a shortly curved spur; lateral petals symmetrical,yellow with red maroon stripes in the upper part (latter unique to Impatiens ). Impatiens beccarii ( Fig. 1c–d View Fig ) has green leaves; lower sepal shallowly navicular and constricted into a curved filiform spur; lateral petals ± asymmetrical, yellow with red or orange markings.Both species are endemic to Sumatra. — Type: H. Wiriadinata 14280 (holo BO), Indonesia, South Sumatra, Muara Enim, Palembang.

Glabrous perennial herbs, up to 80 cm tall; stems erect, simple. Leaves spirally arranged, somewhat congested towards the stem tops, dark green; petiole 1‒3 cm long; lamina ovate to elliptic, 5‒15 by 2.5‒5 cm, base acute, margin crenate, apex obtuse to acuminate, lateral veins 5‒8 pairs. Inflorescences 1– 2-flowered racemes; peduncles c. 3.5 cm long, maroon; bracts linear, 1‒3 cm long. Flowers yellow. Sepals: lateral two ovate, c. 1 by 1 cm, white to maroon; lower sepal deeply navicular, c. 1.5 by 1 cm, constricted into a short curved spur, latter reddish, c. 1.5 cm long. Petals: upper lateral petals usually with maroon stripes in upper part; dorsal petal cucullate, c. 2 by 0.5 cm, yellow with red stripes outside; lower lateral petals united, c. 3 by 1 cm; upper part of each pair oblong to suborbicular, c. 1.5 by 1 cm, yellow with smooth red stripes; lower part of each pair ovate to subovate, c. 1.5 by 1 cm, yellow with red stripes. Ovary glabrous. Fruit unknown.

Distribution — Sumatra (see data of type).

Ecology & Habitat — This newly described species is found growing on the submontane forest floor at altitudes of 1 700 m a.s.l. The specimen was collected flowering in October; further investigations are required to determine the exact flowering and fruiting seasons.

Conservation status — Since this species is only known from one locality at present, a preliminary conservation status of Data Deficient (DD) seems appropriate ( IUCN 2001).