On Mallotus and Deuteromallotus (Euphorbiaceae) in Madagascar

5 Pages·1995·2.3 MB·English

by  G Mcpherson

On
and Madagascar
Mallotus Deuteromallotus (Euphorbiaceae)
in
McPherson
G.
Summary
The genus Deuteromallotus shown to have been based on a misconception and
is its
:
new made new
name to belong in the synonymy of Mallotus, one combination is in that genus, a
Madugasean
and key species provided.
species described, a to the is
is
genre Deuteromallotus base sur une mauvaise interpretation
e est
considere comme synonyme de Mallotus. Une nouvelle combi-
doit etre
t
ne, une nouvelle espece est decrite, et une cle des especes malgaches est proposee.
MO
Gordon McPherson, Missouri Botanical Garden, O. Box 299, Louis, 63166, USA, and
P. St.
m
75005
Laboratoire de Phantrogm Histoin naturelle, 16 Buffon, Paris,
MO
Recently studied material at P and at demonstrates that the characters thought to separate
and no
Mallotus and Deuteromallotus have been misinterpreted, that, in fact, justification exists
&
Hoffmann
Pax genus
As Leandri established the
(1956)
for separation. stated,
this
&
Madagascan acuminatus Pax K. Hoffm.,
Deuteromallotus 1914 hold species D. (Baill.)
in to the
which they considered have a very short style, and a stigma that is scarcely papillose and not
to
wider same paper Leandri established D. capuronii, which he described as
than the style. In the
from
agreeing with the type species in these generically diagnostic characters, but clearly differing
in several minor ways. Webster (1994) placed Mallotus and Deuteromallotus next to one an-
it
Meisner of Tribe Acalypheae Dumortier in the Subfamily
other Subtribe Rottlerinae
in
them.
Acalyphoideae Ascherson, again using primarily the nature of the style to separate
Deuteromallotus
now both species of in fact,
however, the style/stigma in is,
evident, that
It is
The
way from of Mallotus. confu-
an no distinguished that
elongate, coarsely papillose structure in
from which
group's flower, the style/
sion undoubtedly due to the fragility of this pistillate
is
Once
stigma can be easily collected specimens are not immediately pressed. such a loss has
lost if
complete pollen-receiving apparatus
occurred, the mistaking of the stubs of the style base for the
28469
11535 and
(among them, Service Forestier
easily understood. Several collections
is
2556 acuminatus) have thus
586 and (D.
and Scott Elliot
(D. capuronii, Fig. 1-3); Nicoll et al.
1,
on some of the pistillate flowers.
far been found with the style/stigma intact at least
makes following changes necessary.
This
clarification the
Mallotus
Lour., Cochinch. 635
1. Fl. (1790).
:
&
Pax
Deuteroimillotus K. HOFFM., in Engl., Pflanzenr. 63 (4.147.7) 212 (191
:
&
The known
2. species as Deuteromallotus acuminatus Pax K. Hoffm. must, on
(Baill.)
being
transferred to Mallotus, be called M. baillonianus Muell. Arg. because name M. acumi-
the
natus (Blume) Muell. Arg. (Linnaea 34 186, 1865) exists for a Javanese species. In the same
:
Linnaea paper Mueller new name
provided
187), the Mallotus needed
(p. in for the present
M.
capuronii (Leandri) McPherson, comb.
3. nov.
605
(1956, publ. 1957) type Servic
: ; :
In addition, the study of recent collections has revealed following new
the species.
mgenein
DSM,
C, DAV!, EA, ERE, G, GH, K, LE, NY, P!,
Small 4 m, sometimes somewhat
tree to ca. clambering young twigs glabrous or obscurely
;
puberulent, bearing minute
glandular
granules, the older twigs grey and smooth. Leaves opposite,
unequal. Blades x
elliptic to ovate, the smaller 2.6-9 0.9-3.5 cm, the larger 5.0-16.5 x 2.1-8 cm,
somewhat
coriaceous, broadly acute to obtuse at the base, acuminate at the apex, the acumen up
cm
to 2.5 the midrib raised on both surfaces secondaries 6-9 on each side of the midrib, slight-
;
;
and
ly raised flattened on the lower surface, lighter in colour than the rest of the lower surface
;
both
surfaces without
glandular granules, the upper surface glabrous, the lower surface glabrous
or minutely
appressed-puberulent except for the hairs surrounding the domatia domatia some-
;
what
elongate and
sunken,
in the axils of the secondary veins, bordered by long
at least initially
Shorter
hairs. petioles 0.5-2.3 cm, the longer 1.2-6.5 cm, terete or narrowly caniculate, markedly
pulvinate at both ends, the upper pulvinus usually erect-puberulent, as sometimes the rest of the
is
mm,
petiole. Stipules subulate, 3-5
glabrous, caducous.
Plants dioecious or monoecious. Staminate
inflorescences racemose, and
terminal in the axils
of uppermost
the leaves, the axis 1-2.5 cm, puberulent and
glandular-granular resinous bracts
to
;
flower and bracts after
McPherson habit pistillate
capuronii (Leandri) 1, 2, —
: ;
Mallotus spini
28469).
Forestier
ig adaxial stigmatic surface (Service
atypical
(including,
inflorescence
5 ovary portion of staminate ly,
ver • • 6,
Forestier 4903).
Service
(4,5,BoJr6626
' 7, «.
, \
;
—
—
172
mm
mm
mm,
subulate, 2-3 pedicels 1.5-2 jointed near the base buds 2-2.5 in diameter sepals
; ; ;
x mm, mm,
3(-4) in number, 1.5 1.5 resinous stamens ca. 100 in number, ca. 2.5 the filaments
;
mm, mm.
and
ca. 2 the anthers ca. 0.3 Pistillate inflorescences terminal in the axils of the upper-
cm
mm,
most
leaves peduncles (2.5)5-11 bracts subulate, 3-5 glabrous flowers
pistillate soli-
; ; ;
tary or in few-flowered clusters at the end of the peduncle, sessile calyx of 5-6 subulate sepals 2-
;
mm
mm, cm
4 glabrous
styles (2?-) ca. long, ca. 0.5 in diameter, papillose.
3,
1
;
mm mm
Fruit ca. 5 high, ca. 8 in diameter, usually minutely and sparsely stellate puberulent,
mm)
sometimes resinous, spinulose, each sixth of the capsule bearing 1-2 large spinules (l-2(-4)
mm mm
mm)
and 0-2 smaller spinules (ca. 0.5 column 4 high seeds roughly spherical, 4 in
; ;
and
northern forests at elevatic
l
—
Km
Material Madagascar
studied. Bosser 6626, route Moramanga-Anosibe, IX. 1953,
15, fl.
:
(P) Cours 1205, District d'Ambatondrazaka, 950 m, XI. 1938, (P) Decary 6519, Ambila, au Sud de
fl.
;
;
Tamatave, 0.V.1 928, (P) Herbier du Jardin Botanique de Tananarive 4353-D, Lac Alaotra, (P)
1 fl. s.d., fl.
;
&
McPherson
van der Werjf 16415, Prov. Antsiranana, Manongarivo Massif, E. of Ankaramy, 1100-1175 m,
(MO)
19.X. 1994, Peltier 5998, Ambatovy, VII. 1966, (P) Rabevohitra 2052, Prefecture deTolagnaro
fr. 1. fl.
; ;
(MO)
(Fort Dauphin), Ste Luce, 20.X.1989, Reserve Naturelle 12031, Distr. d'Ambatondrazaka,
fl.
:
&
km
Manakambabiny-Est, Lowry Ambila-
22.111.1962, (P) Schatz 1301, Prov. Tamatave, N. of
fl.
1
;
MO,
Lemaitso, dune 0-50 m, (DAV, Ambila-
coastal forest, 4.IV.1987, P) Service Forestier 2937,
fl.
;
Mahambo,
Lemaitso, s.d., (P) 4903, Distr. de 14.111.1952, (P) 5857, Ambila-Lemaitso, 10.X.1952,
fl. fr.
; ;
(P) 7474, Ambila-Lemaitso, 6.XI.1952, bout. (P) 18064, Est Foret sublittorale, sur sables, a Ambila-
fl.
;
; :
Mahambo,
Lemaitso, 8-10.VIII.1957, (P) 22113, entre Foulpointe Fenerive, a 25.XI.1962, (P).
fr. et fr.
;
Mallotus had been
oppositifolius (Geisler) Muell. Arg., the widespread African species that
now known
thought to be the only representative of the genus Madagascar, thus one of four
in
is
Madagascan They
species. can be separated using the following key.
Leaves obovate to oblanceolate, the apex obtuse or emarginate, or rarely broadly short-acuminate ....
M. capuronii
Leaves
ovate or apex long-acuminate 2
elliptic,
Twigs
densely pubescent M. baillonianus
2.
Twigs
2'. glabrous or obscurely farinose-puberulent 3
3. Leaves with two prominent basal veins differentiated from the others, abaxial surface bear-
ing glandular granules smooth M.
fruit opp<
;
y
Leaves
pinnately veined, the basal veins undifferentiated, abaxial surface without glandular
.
granules spinulose M. spinulosus
fruit
;
Acknowledgements
thank Morat, Phanerogamic
Professeur Ph. Directeur, Laboratoire de
I
:
useum
national d'Histoire naturelle for facilitating this study, much of which was financially supported by
Museum
through Visiting Scholar programme. thank Monsieur D. Storez drawing
i its (P) for carefully
I
—
—
173
REFERENCES
—
M. Capuron.
Leandri, 1956 (publ. 1957). Euphorb ouvelles recoltees par R. Bull.
J.,
France 604-608.
103
Soc. Bot.
:
—
& Das
Hoffmann, Euphorbiaceae-Anilxplicuc-Mcirunaliiicw 212, Engl.,
Pax, 1914. in
K.,
F.
:
63
Pflanzenreich (4.147.7).
—
Webster, G. 1994. Synopsis of the genera a
L.,
Card. 33-144.
Bot. 81
: