Revision and new species of the African genus Mischogyne (Annonaceae)
Author
Gosline, George
Author
Marshall, Andrew R.
Author
Larridon, Isabel
text
Kew Bulletin
2019
2019-06-30
74
28
1
23
journal article
10.1007/S12225-019-9804-7
1ed5ac34-1b70-4189-a175-7526621e1705
0075-5974
3345047
1.
Mischogyne congensis
Gosline
sp. nov.
Type
:
Congo
(
Kinshasa
), Yambuya,
9 Nov. 1956
,
Eorard
2000 (holo-
t y p e B R* [B R6 10 2 0 0 2 2 7 0 3 9 0], i s o t y p e K! [K000874272]).
http://www.ipni.org/urn:lsid:ipni.org:names:60478273-2
Uoariastrum ellioitianum
sensu Boutique,
non
U. elliotianum
Engl. & Diels (
Boutique 1951
)
.
Small tree
3 – 7 m
tall, to
9 cm
diam.; branches and twigs glabrous; very young twigs with sparse brown appressed hairs
0.1 – 0.4 mm
long.
Taeigs
light grey to brown, roughly striate, glabrescent, youngest shoots and shoot buds covered with light brown hairs
0.1 – 0.4 mm
long.
Petioles
5 – 10 mm
long,
1 – 2 mm
in diam., glabrescent, drying black; very young petioles with sparse hairs
0.1 – 0.3 mm
long.
Leaf
lamina narrowly obovate to elliptic,
10 – 18 cm
long,
3.5 – 6 cm
wide, length:width ratio 2 – 3.5, apex acuminate to caudate, acumen triangular to linear,
1 – 3 cm
long,
0.2 – 0.5 cm
wide at mid-length, base cuneate, coriaceous, glabrous on both surfaces, glossy green above and below, drying glossy green to matte light green; midrib glabrous; secondary nerves 8 – 9, gradually ascending at 10° – 30° angle to midrib to 10 – 20% of the leaf length before anastomosing, glabrous.
Floaeers
1 (– 2?) on leafy branches. Flower buds ovoid,
0.6 – 0.8 cm
long,
0.5 – 0.6 cm
in diam., with slightly obtuse apex. No bracts seen. Flowering pedicel
0.2 – 0.9 cm
long,
0.6 – 1 mm
in diam., densely pubescent, hairs
0.05 – 0.2 mm
long, appressed, brown.
Sepals
oblong,
0.8 – 1 cm
long,
0.5 – 0.6 cm
wide, length:width ratio 1.5, base rounded, apex obtuse, pubescent outside and inside, hairs
0.05 – 0.1 mm
long, light green when fresh, brown in herbarium material.
Petals
narrowly ovate,
2 cm
long,
0.5 cm
wide, length:width ratio 4, base rounded, apex rounded, outer surface with dense straight appressed hairs
0.2 – 0.5 mm
long, inner surface with soft curling hairs
0.1 mm
long, glabrescent, white when fresh.
Torus
cylindrical,
2 – 3.5 mm
long,
1 – 1.3 mm
diam., densely pubescent with stiff white semi-erect hairs
0.8 – 1.2 mm
long directed towards apex.
Stamens
not seen.
Carpels
9 – 16, 3 –
4 mm
long,
1 – 2 mm
in diam., indumentum as torus; stigma sessile,
0.6 – 0.8 mm
diam., drying black.
Fruits
with only one mature monocarp in specimen seen. Monocarp ovoid,
6 cm
long,
3 cm
in diam., with a soft brown indumentum when dried, stipe
1 cm
long,
0.4 cm
in diam. Seeds not seen.
Figs 2C
,
3
.
RECOGNITION
. Similar to
Mischogyne elliotiana
in being a small rainforest shrub or tree with leaves less than
20 cm
long, but differing in: many leaves having a linear acumen arising from the rounded apex of the leaf and 5 times or more as long as wide rather than apex attenuate or acuminate with a triangular acumen 1 – 3 times long as wide; secondary nerves ascendant 10 – 25% of the leaf length before anastomosing at a distinct angle to a marginal nerve vs ascendant 25 – 30% of the leaf length before anastomosing almost parallel with the margin; the leaves drying dark glossy green above and below rather than matte below; the older petioles glabrous rather than having at least some indumentum (
Fig. 3
).
DISTRIBUTION
.
Democratic Republic of Congo
(
Map 1
).
SPECIMENS EXAMINED.
DEMOCRATIC REPUBLIC OF CON-GO
.
Équateur province
:
Yalisenga (Mondombe)
380 m
, [
0°43'30"S
22°40'32"E
], fr,
21 April 1959
,
C. M. Eorard
6205
(
BR
*,
K
!);
ibid., fl fr,
26 Dec. 1958
,
C. M. Eorard
5376
(
K
!)
.
Orientale province
:
Busukulu Village
,
Environs do Yangambi Reserve
no. 121/
Agri
1953, [
0°43'N
24°36'E
],
30 Sept. 1947
,
J. Leonard
1461 (
BR
*)
;
ibid.,
1 Aug. 1947
,
J. Leonard
1311 (
BR
*,
K
!,
P
*);
Bengamisa Yangambi Bengamisa Route vers
45 km
,
450 m
, [
0°56'28"N
25°12'23"E
], fl,
21 May 1936
,
G. Gilbert
2321bis
(
BR
*,
K
!,
P
*);
Yambuya
,
400 m
, [
1°15'3"N
24°33'5"E
], fl,
1 Nov. 1956
,
C. M. Eorard
2000
(
BR
*,
K
!,
P
*)
.
HABITAT
. Riverine forest. Semi-deciduous forest.
CONSERVATION STATUS
. This taxon is only known from six specimens and four locations on the
Congo
, Aruwimi, Lindi, and Tshuapa rivers in the
Democratic Republic of Congo
. The Meise herbarium has 5339
Annonaceae
specimens from the
DRC
, many collected near the biological research station at Yangambi. The existence of only six specimens indicates that the species is rare. The area around Yangambi on the
Congo
is subject to continuing urbanisation as seen in satellite images. All the locations appear to be impacted by shifting cultivation (Google Earth 2018). Tree cover loss in the 2000 hectares including Yangambi was 18% from
2000 – 2017
. Loss along the Lindi river is 45% in this period (
Hansen
et al.
2013
). Threats from deforestation along the rivers appear to be substantial. The four locations give an EOO of
11618 km
2
and an AOO of
16 km
2
. The indicated
IUCN
rating is Endangered B1&2ab(iii).
PHENOLOGY
. Flowering in November, December, May. Fruiting April.
VERNACULAR
NAME
. Inaola a loopa (Turumbu,
Leonard
1311).
USES
. The leaves and crushed fruits are applied by scarification on the bites of snakes. The local people say that snakes eat a lot of the fruit of this shrub (
Gilbert
2321bis).
NOTES
. These specimens have previously been determined as
Mischogyne elliotiana
var.
glabra
. Their geographic isolation led us to take a closer look. The secondary venation and abrupt long linear acumen indicated a distinct taxon and the molecular phylogenetic hypothesis confirms this taxon as being in a clade with
M. michelioides
and
M. iddii
, the Angolan and Tanzanian taxa, and in a different clade from
M. elliotiana
.