Evolution of Impatiens (Balsaminaceae) in the Albertine Rift – The endemic Impatiens purpureoviolacea complex consists of ten species
Author
Fischer, Eberhard
0000-0001-7455-9833
Institut für Integrierte Naturwissenschaften – Biologie, Universität Koblenz-Landau, Universitätsstrasse 1, 56070 Koblenz, Germany
efischer@uni-koblenz.de
Author
Abrahamczyk, Stefan
0000-0001-8047-932X
Nees Institute for Biodiversity of Plants, University of Bonn, Meckenheimer Allee 170, 53115 Bonn, Germany
sabraham@uni-bonn.de
Author
Holstein, Norbert
0000-0001-9892-0355
Natural History Museum, Cromwell Rd., London SW 7 5 BD, United Kingdom
n.holstein@nhm.ac.uk
Author
Janssens, Steven B.
Botanic Garden Meise, Nieuwelaan 38, Meise, 1860, Belgium
steven.janssens@plantentuinmeise.be
text
TAXON
2021
2021-09-06
70
6
1273
1299
http://dx.doi.org/10.1002/tax.12566
journal article
2599
10.1002/tax.12566
495154d8-5ca2-4a89-8b30-574f579034cb
1996-8175
5849572
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
.
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).
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.
Fig. 14.
Impatiens elwiraurzulae
.
A
, Leaf, upper surface;
B
, Leaf, lower surface;
C
&
D
, Inflorescence;
E
, Flower;
F
, Lower sepal with spur;
G
, Dorsal petal;
H
&
I
, Lateral united petals;
J
, Bracts, pedicel, lateral sepals and anthers. — Scale bar: 1 cm. A–J,
Dumbo & Dumbo s.n
., Democratic Republic of the Congo, Mulolo.
Etymology. –
Named after the occasional but regular colour change of single flowers from white to pink.