Impatiens versicolor 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 : 1290-1292

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

Holotype: Rwanda. Western Province, Nyungwe National Park, road 7 km south of Pindura towards Bweyeye , rocks and wet roadsides, 1800– 1900 m, 8 Mar 2013, E. Fischer 13390 (BR barcode BR0000014532108 !; isotype: BONN! ).

Diagnosis. – Impatiens versicolor belongs to the group with glabrous ovary. It differs from I. ludewigii in the white flowers, with occasionally single pink flowers appearing on the same plant, the dorsal petal divided to less than 1/3 of its length, the plants densely hairy on upper leaf surface, stems and pedicels, later glabrescent, the leaves at margin with 10– 15 pairs of extrafloral nectaries, and the often suberect habit.

Description. – Plants erect to suberect or ascending, usually glabrous or only with loose hairs, or sometimes densely hairy on upper leaf surface, stems and pedicels later glabrescent, stems 20–50 cm long. Leaves with 4–8 cm long petiole, petiole with 0–2 (4) pairs of extrafloral nectaries, lamina ovate, acuminate, 35–46 × 21–34 mm, margin with 10–15 pairs of extrafloral nectaries. Inflorescence with (1) 2 flowers, peduncle 5.5– 16.5 mm long, pedicel 11–18 mm long. Flowers white, petal base barely yellow, purple maculae at base large, occasionally single pink flowers appearing on the same plant. Lateral sepals 4.5–6.5 × 1–2 mm. Lower sepal navicular, 7–9 mm long and 3– 4.5 mm deep, abruptly constricted into a spiraled, usually filiform spur, 13–19 mm long. Dorsal petal divided to less than 1/3 of its length, 7–11 × 10.5–16.5 mm. Lateral united petals up to 23 mm long, upper lateral united petals 10–18 × 5–7.5 mm, not overlapping lower lateral united petals, base of upper lateral petal with dark pink or red and yellow maculae, lower lateral petal 13–19.5 × 5–7.5 mm. Ovary glabrous, 4– 5 mm long. Fruit glabrous, 13 × 6 mm. Figures 2 , 6D–E , 15 .

Ecology. – Wet rocks and roadbanks in montane rainforest, 1800–1900 m.

Distribution. – Rwanda, only known from Nyungwe National Park, only recorded in a valley south of Pindura towards Bweyeye.

Etymology. – Named after the occasional but regular colour change of single flowers from white to pink.

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. 6. Seeds of the Impatiens purpureoviolacea complex. A–C, Impatiens ludewigii: A & B, Seed; C, Detail of testa. D & E, Impatiens versicolor: D, Seed; E, Detail of testa. F & G, Impatiens gesneroidea: F, Seed; G, Detail of testa. — Scale bars: A, 600 μm; B, 500 μm; C, 100 μm; D, 400 μm; E, 70 μm; F, 400 μm; G, 100 μm. A–C, Fischer 13912, BG Bonn 37754; D & E, Fischer 13988, BG Bonn 34557; F & G, Fischer 11021, BG Bonn 32578.

Fig. 15. Impatiens versicolor. A, Detail of habit; B, C & E, Flower, frontal view; D & F, Flower, lateral view. — A–F, Fischer 13390, Rwanda, between Pindura and Bweyeye.