Impatiens arguta Hook. f. & Thomson

Impatiens species are annual, perennial or suffruticose herbs, terrestrial or sometimes epiphytic. Stems erect or procumbent, woody, herbaceous, succulent, stoloniferous or monoliform, usually rooting at lower nodes. Leaves radical or cauline, opposite, alternate, whorled or verticellate, variable, lanceolate-oblong to ovate-elliptic, base cuneate to obtuse, margins entire to crenate-dentate, apex obtuse to acuminate, petiolate or subsessile, exstipulate, sometimes with stipular gland at the base of petiole. Inflorescence resupinate, axillary subumbellate, racemes, fascicled or solitary. Flowers bisexual, zygomorphic, pedicellate, bracts persistent or caducous, sepals 3 or rarely 5, imbricate, 2 lateral ones flat, small, linear lanceolate-ovate, usually green, posterior sepal (Lip) large, petaloid, bag-shaped, navicular or saccate or spurred, petals 5, free, red, scarlet, purple, greenish or white, upper standard petal, flat, keeled or cucullate, entire or crested, usually lobed, lateral ones (wings or alae), fused in pairs, entire or lobed, sometimes with slender appendage at the base, Stamens 5, alternating with petals, free or fused towards the apex, connate or sub-connate, somewhat like a ring surrounding the style and stigma, filaments broad and short, anthers bi-locular. Ovary 5 locular, superior, oblong-ovoid, ovules many, 1 seriate in each cell, style 1, very short or absent, stigma 5 celled, sessile. Fruit indehiscent, capsule, often asymmetrical, swollen in the middle, loculicidally dehiscing by 5 valves, springing away elastically from axis, glabrous or hairy. Seed flattened or oval, smooth or tuberculate, glabrous or hairy, albumen absent.

Impatiens species flowers are complete, bisexual, i.e., with functional male (androecium) and female (gynoecium), including stamens, carpels and ovary. Pollination is entomophilous i.e., by insects, or cleistogamy i.e., by self or allogamy i.e., by cross pollination. Flowering/Fruiting: July—October.

Seeds primarily dispersed by autochory i.e., self dispersal, may be later by zoochory i.e., dispersal by birds or animals, anthropochory i.e., dispersal by humans.

Perennial herbs, about 30-70 cm tall. Stems erect, much branched, glabrous. Leaves alternate, lanceolate-ovate, about 3-15 x 2-5 cm across, base cuneate, margins subentire or serrate, apex acute to acuminate, lateral veins about 7-11 on either side of the midrib, green above and paler beneath, minutely pubescent both above and beneath, petiole slender, about 1-3 cm long, exstipulate, but with 2 stipular glands at the base. Inflorescence resupinate, axillary, 1-2 flowered, in the upper parts of the plant, usually glabrous. Flowers bisexual, zygomorphic, purplish or dark blue, pedicel slender, about 2-4 cm long, bracts 2, setaceous near the base, sepals 4, imbricate, 2 lateral ones flat, small, dimidiate-ovate, usually green, apex cuspidate-acuminate, glabrous, about 5-9 x 2-5 mm across, inner ones narrow lanceolate, , posterior sepal (Lip) large, petaloid, elongate, shallow navicular, bucciniform, spurred shortly, petals 5, free, yellow, upper standard petal, keeled or cucullate, obovate-obcordate, entire or crested, bilobed, apex shallow emarginated, dorsally spurred, lateral ones (wings or alae), fused in pairs, basal lobes ovate, distal lobes, not clawed, curved upwards, about 2.5 cm long, dorsal auricle present. Stamens 5, alternating with petals, anthers bi-locular, obtuse. Ovary 5 locular, superior, oblong-ovoid, ovules many, 1 seriate in each cell, style 1, very short or absent, stigma 5 celled, sessile. Fruit indehiscent, capsule, narrow fusiform or linear, swollen in the middle, about 1-4 x 0.2-0.5 cm across, loculicidally dehiscing by 5 valves, springing away elastically from axis, glabrous. Seeds many, globose or oval, shining, glabrous, albumen absent.

Impatiens species are susceptible to various insect pests, virus and fungi, affecting leaves, fruits and roots.

Along streams, thicklets and grassy slopes of Eastern Himalayas, altitude 900-2100 m.

Not evaluated (IUCN).

Used in folk medicine.