Impatiens hydrogetonoides Launert

Perennial herb up to 70 cm. tall, but usually less, often only 15 cm.; stems erect, usually solitary, arising from a crown supporting a number of thin tuberous, rather fleshy, roots, unbranched or with a few short lateral shoots.. Leaves crowded towards the stem apices, spirally arranged; petiole 0.8–5.6 cm. long, slender; lamina lanceolate-elliptic to elliptic or oblanceolate, 2.8–13 cm. long, 1.4–7.5 cm. broad, attenuate at the base, the apex obtuse to long-acuminate, sparsely pubescent above, glabrous or sparsely pubescent on the veins beneath; lateral veins 3–8 pairs; margin crenate to crenate-serrate, generally with a few ± 1 mm. long fimbriae towards the base where the lamina runs along the petiole.. Flowers in fascicles of 2–3, or solitary, ependunculate, pale pink to lilac or deep rose-purple, the upper petal of each lateral pair usually with a dark blotch towards the base.. Bracts linear-subulate, 3–4 mm. long, inconspicuous.. Pedicels 2.9–7.8 cm. long, slender, glabrous or sparsely pubescent, deflexed in fruit.. Lateral sepals ovate to lanceolate, 5–11 mm. long, 2.5–3.5 mm. broad, acuminate.. Lower sepal obliquely and narrowly navicular, 8–14 mm. long, 3–5 mm. deep, abruptly constricted into a 18–25 mm. long curved filiform spur.. Dorsal petal 11–13 mm. long, 12–19 mm. broad (when flattened), semi-cucullate, dorsally with a narrow crest terminating in a short acute point.. Lateral united petals 18–27 mm. long, the upper petal of each pair about one-third the size of the lower; upper petal ovate-oblong, 6–13 mm. long, 4–19 mm. broad, usually apiculate; lower petal transversely ovate or semiorbicular, 12–17 mm. long, 9–14 mm. broad, with a slight emargination along the inner margin.. Ovary glabrous.. Immature fruit narrowly fusiform, ±11 mm. long and 4 mm. broad, glabrous.