Impatiens oppositifolia L.

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.

Flowering class: Dicot Habit: Herb

Flowering and fruiting: July-October

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: February—December.

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.

Annual herbs, flaccid, about 20-40 cm tall. Stems slender, erect, tetragonous, simple or branched, with elongated internodes, glabrous. Leaves opposite decussate, linear lanceolate to linear oblong, upper ones broad and auricled, about 2.5-7.5 x 0.3-0.7 cm across, base broad or rotund, margins entire or remotely serrate with bristle serratures, apex acute to acuminate, membranous, coriaceous, green above and paler beneath, minutely pubescent above and glabrous beneath, veins impressed above and prominent beneath, petiole very short to sessile, stipules subulate. Inflorescence resupinate, axillary, solitary or binate in the leaf axils. Flowers bisexual, zygomorphic, violet to purplish, rarely white with pink tinge, about 1.5-2 cm across, pedicel slender, distinctly long hairy, deflexed in fruit, about 2-3 cm long, deflexed or elongated in fruit, about 3-4 cm long, sepals 3, imbricate, 2 lateral ones flat, almost half the length of the flower, linear lanceolate, apex acuminate, with a green tip, sparsely long hairy, posterior sepal (Lip) large, petaloid, with rose colored prominent honey guides, back with prominently multiple ribbed, without a yellow eye inside, funnel shaped or deeply cymbiform, hairy at the base and back, spurred, spur very small, green, hairy, incurved like a hook, apex apiculate, upper standard petal, orbicular, keeled, hairy in a row on keel backside, prominently crested at the base of the keel, about 2 mm across, lateral ones (wings or alae), narrow stipitate at the terminal lobe, basal lobes erect small, falcate, apex acute, distal lobe short, obovate-orbicular, about 0.7 x 0.9 cm across, dorsal auricle short, apex obtuse, with two opposite auricles facing each other. Stamens 5, filaments subulate, anthers bi-locular, pollen white, pink, 4 colpate, squarish or rectangular, smaller about 26 x 26 µ, exine minutely reticulate, Androecium deflexed towards the mouth. Ovary 5 locular, superior, oblong-ovoid, straight, apex acute and incurved. Fruit indehiscent, capsule, ellipsoid, slightly swollen in the middle, tapering at the both ends, about 0.8-1.5 cm long, apex shortly stipitate, glabrous. Seeds many, sub-globose, blackish or chest brown, shining, glabrous.

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

Notes: Western Ghats, Moist Localities

Open grasslands of Western Ghats, altitude up to 600 m.

Evergreen forests and grasslands

Not evaluated (IUCN).