Revision of the genus Monotes (Dipterocarpaceae) in D. R. Congo, with implications for Angola and its distinction from Marquesia
Author
Meerts, Pierre
Herbarium et bibliothèque de botanique africaine, Université Libre de Bruxelles, Avenue F. D. Roosevelt 50, CP 244, B- 1050 Brussels, Belgium
Author
Rougelot, Quentin
Herbarium et bibliothèque de botanique africaine, Université Libre de Bruxelles, Avenue F. D. Roosevelt 50, CP 244, B- 1050 Brussels, Belgium
Author
Sosef, Marc
Botanic Garden Meise, Nieuwelaan 38, B- 1860 Meise, Belgium
text
Phytotaxa
2017
2017-06-07
308
2
151
205
http://dx.doi.org/10.11646/phytotaxa.308.2.1
journal article
10.11646/phytotaxa.308.2.1
1179-3163
13701270
3.
Monotes autennei
Duvigneaud (1958: 183)
Type
:
—D.R.
CONGO
. Kahundu, Dilolo, forêt claire à
Brachystegia boehmii
,
23 May 1957
,
Duvigneaud 3267MI
(
holo-
: BRLU! [barcode BRLU0000090020735],
iso-
: BRLU! (3 sheets)).
Tree up to
17 m
high; branchlets shortly puberulous to densely pubescent. Leaf: petiole
10–25 mm
long, very thick (
3–3.5 mm
in diameter); blade broadly elliptic, obovate, sometimes suborbicular, (7–)12–18(–22) × (5–)9–12(–14) cm, leathery, broadly cordate to rounded at the base, obcordate-bilobate or deeply emarginate at the apex, typically with the apical sinus deeper than the basal one, often with extra leaf-glands in the axils of the lateral nerves; lateral nerves 12–15 pairs, slightly incurved, some of them bifurcate near the apex, nerves and bifurcations reaching the margin of the leaf; upper surface slightly scaberulous with short straight hairs
0.15–0.3 mm
long in fascicles of 2–8 on small white cushions, finally glabrous; lower surface greyish- or fulvous-pubescent (sometimes glabrescent when old), with relatively long curved hairs mixed with fasciculate ones, and with the interreticular areoles densely to sparsely covered with minute stellate hairs; midrib very thick and prominent beneath; veins and reticulation very prominent and forming deep cavities. Inflorescences, flowers and fruits as in
M. katangensis
.
Illustrations:
—
Figs. 3D
,
4D
,
5B,C
,
7A,B
,
13
.
Distribution in D.R.
Congo
:
—Widespread in Upper
Katanga
, apparently more frequent in the west.
Distribution elsewhere:
—
Zambia
. Restricted distribution.
Habitat and ecology:
—Miombo woodland; mixed high woodlands with
Marquesia acuminata
and
M. macroura
on grey compact soil; chipya on Kalahari sand.
Other
representative specimens examined:—D.R.
CONGO
.
Upper
Katanga
:
20 km
E of Kasagi, territ.Kisenge, forêt à
Marquesia
sur terre grise compacte à petites termitières,
Duvigneaud & Timperman 2317Mo1
(BRLU!);
15 km
N of Dilolo, forêt claire de plateau à
Marquesia
sur sol gris,
21August 1956
,
Duvigneaud & Timperman 2424
(BRLU!); Tshisenge,
17 km
N of Dilolo, forêt claire à
Marquesia
sur sol gris compact, 1957,
Duvigneaud 2428M
(BRLU!); Dembo de la Lufupa, forêt claire de bordure à
Brachystegia longifolia
et
Cryptosepalum pseudotaxus
,
Duvigneaud & Timperman 2541
(BRLU!); Kalongwe, brousses denses avec
Monotes caloneurus
,
9 May 1957
,
Duvigneaud 3090M
(BRLU!); Kolwezi, Colline D, forêt claire sur roches siliceuses cellulaires,
13 June 1957
,
Duvigneaud 3494M
; Nzilo, forêt verger sur terre compacte,
14 June 1957
,
Duvigneaud 3516M
(BRLU!); Kyamandjizi, forêt claire,
8 October 1981
,
Malaisse 11939a
(BR!); route Nzilo-Le Marinelle, km 1.5, crête au dessus du barrage, formée de quartzite et de quartzophyllades,
21 September 1958
,
Plancke 111/1532
(BRLU!).
Discussion:—
Monotes autennei
is generally easy to recognize by its large bilobed leaves with fasciculate hairs on the upper surface. Many specimens had been misidentified as
M. katangensis
or
M. magnificus
. Intermediates with
M. katangensis
are frequent (see note under that species). Some collections have a rounded leaf apex and ovate-elliptic leaves (
Desenfans 4012
(BRLU!)).
References:—
Duvigneaud (1961: 414)
;
Lebrun & Stork (1991: 144)
; Meerts (2016: 222).