Impatiens lotteri Eb.Fisch., Abrah., Holstein & S.B.Janssens, 2021

Fischer, Eberhard, Abrahamczyk, Stefan, Holstein, Norbert & Janssens, Steven B., 2021, Evolution of Impatiens (Balsaminaceae) in the Albertine Rift – The endemic Impatiens purpureoviolacea complex consists of ten species, TAXON 70 (6), pp. 1273-1299 : 1292-1293

Impatiens lotteri Eb.Fisch., Abrah., Holstein & S.B.Janssens , sp. nov. –

Holotype: Democratic Republic of the Congo, South Kivu, Ulindi River , S03°05.625′ E28°31.868′, 1803 m, 17 Aug 2008, M.C. Lotter 1542 (BR barcode BR0000005438105 !).

Diagnosis. – Impatiens lotteri belongs to the group with glabrous ovary. It differs from I. ludewigii and I. versicolor in the upper lateral united petals 9–10 × 10 mm, distinctly overlapping the lower lateral united petals, thus giving the flower an almost circular appearance, and the entirely glabrous plants.

Description. – Plants ascending to erect, glabrous, stems 30 cm long. Leaves with 16 mm long petiole, petiole with 2–4 pairs of extrafloral nectaries, lamina ovate, discolourous, 53 × 25 mm, margin with 14–16 pairs of extrafloral nectaries. Inflorescence with 1 flower, peduncle 26 mm long, pedicel 11 mm long. Flowers pink, upper petal base barely yellow, purple maculae at upper petal base large. Lateral sepals 6– 7 × 2 mm. Lower sepal navicular, 8–9 mm long and 5– 6.2 mm deep, abruptly constricted into a spiraled, usually filiform spur, 18–20 mm long. Dorsal petal 10–12 × 7–10 mm. Lateral united petals up to 20 mm long, upper lateral united petals (5) 9–10 × 10 mm, distinctly overlapping lower lateral united petals, lower lateral petals 12 × 5–6 mm. Ovary 4– 5 mm long, glabrous. Figures 2 , 13E .

Ecology. – Montane rainforest at 1800 m.

Distribution. – Democratic Republic of the Congo, only known from the type locality at the Ulindi River.

Etymology. – Named after Mervyn C. Lotter, who discovered the species.

Figures

Fig. 2. Distribution map of the eight insect-pollinated species of the Impatiens purpureoviolacea complex. Dots indicate species with hairy ovaries, and stars mark species with glabrous ovaries.

Fig. 13. A–D, Impatiens elwiraurzulae. A & C, Flower, frontal view; B, Flower, lateral view; D, Flower showing only slightly coiled spur. E, Impatiens lotteri, detail of habit with flower. — A–D, Dumbo & Dumbo s.n., Democratic Republic of the Congo, Mulolo; E, Lotter 1542, Democratic Republic of the Congo, Ulindi River (Photo: M.C. Lotter).