Taxonomic novelties in Apocynaceae subfam. Asclepiadoideae from New Caledonia
Author
Meve, Ulrich
Department of Plant Systematics, University of Bayreuth DE- 95448 Bayreuth (Germany)
Author
Gâteblé, Gildas
Institut agronomique néo-calédonien, Station de Recherche agronomique de Saint-Louis, boîte postale 711, F- 98810 Mont-Dore (New Caledonia)
Author
Liede-Schumann, Sigrid
Department of Plant Systematics, University of Bayreuth DE- 95448 Bayreuth (Germany)
text
Adansonia
2017
2017-06-30
39
1
55
70
journal article
10.5252/a2017n1a5
2ca41b6f-e201-4093-9c51-f79abb72b834
1639-4798
4599043
Marsdenia neocaledonica
Meve, Gâteblé & Liede
,
sp. nov.
(
Figs 1B, C
;
5
)
Similar to
M.microstoma
but differing in being erect to occasionally twining, sarmentose shrubs with densely and mostly distichously arranged, short, linear leaves, and campanulate flowers that do not exceed
3 mm
in length.
TYPUS. —
New Caledonia
.
Grande-Terre
, North Prov.,
Koumac
,
Siounda
,
200 m
alt., in maquis on serpentine soil,
22.IV.1967
,
M.S.MacKee
16662
(
holo-
,
P
[
P00607336
]!)
.
PARATYPI. —
New Caledonia
.
Grande-Terre
, North Prov.:
Kafeate
,
12.XII.1950
,
M
.
Baumann-Bodenheim 9623
(
P04258708
,
Z000052709
)
;
Pindai
,
14.V.1992
,
T
.
Jaffré 3156
(
NOU017801
, P04237233)
;
Vallée de la Koumac
,
30 m
,
19.IV.1967
,
H.S
.
MacKee 16598
(P04237234)
;
Baaba
,
Pointe
Sud-ouest,
5-20 m
,
6.I.1971
,
H.S
.
MacKee 23212
(P04237231)
;
Poum
,
Anse de Pouani
,
5 m
,
17.II.1971
,
H.S
.
MacKee 23336
(
NOU057837
, P04237232)
;
Koné
,
Pinjen
,
50 m
,
25.IV.1971
,
H.S
.
MacKee 23654
(P04237228)
;
Gomen
,
Cap Deverd
,
20 m
,
10.IV.1975
,
H.S
.
MacKee 30019
(
NOU057777
, P04237229)
;
Plaine des Gaiacs
,
20 m
,
12.VIII.1977
,
H.S
.
MacKee 33588
(
NOU017800
, P04237230)
;
Koumac
,
Siounda
,
200 m
,
13.V.1978
,
H.S
.
MacKee 35147
(
NOU017802
,P04237225)
;
Néhoué
,
Babouillat
,
5 m
,
9.V.1979
,
H.S
.
MacKee 36861
(
NOU017819
, P04237226)
;
Koumac
,
Tangadiou
,
50 m
,
9.V.1979
,
H.S
.
MacKee 36874
(P04237227)
;
Voh
,
Katepaik
mountain,
4.IV. 2016
,
G
.
Gâteblé 760
(NOU)
;
Ouaco
,
Néchoua
,
100 m
,
18.V.1981
,
H.S
.
MacKee 39095
(
NOU017818
, P04237224)
;
Montagnes de Gomonen près Gatope
, 1861-1867,
E
.
Vieillard 2999
(P04237221, P04237222, P04237223) and
E
.
Vieillard 3000
(P04237219, P04237220)
.
The following sterile specimens probably also belong to
M. neocaledonica
,
sp. nov.
:
Siouda
,
20.I.2004
,
G
.
Dagostini 754
, (
NOU001304
, P04526643)
;
Poum
,
13.XI.1990
,
I.H
.
Müller 186
(P04564507)
;
Pagoumene
,
VIII.1967
,
A
.
Nothis 564
(P04593762)
.
ETYMOLOGY. — While so many species of
Marsdenia
are endemic to New Caledonia, none has previously been named after the archipelago, where the new species is only found in the northwest of Grande-Terre.
DISTRIBUTION AND HABITAT. —
New Caledonia
. Grande-Terre northwest and Baaba island, North Prov. (
Fig. 3
). On serpentine sites at the base of northwest ultramafic massifs or on serpentine veins in maquis close to the coast, receiving comparatively little precipitation (
800
-
1200 mm
/p.a.);
5-200 m
altitude.
CONSERVATION STATUS. — This species has a northwest pattern of distribution at low altitudes on serpentine soils between Plaine des Gaiacs in the south and Baaba island in the north. There is no or very little nickel mining in these places and bush fires are the main issue for conservation of plants in those localities. With about ten localities, an EOO of
1075 km
² and an AOO of
44 km
², we are assigning a preliminary IUCN conservation status of “Near Threatened” using Red List criteria (
IUCN 2012
).
DESCRIPTION
Plants
Erect to ascending shrubs, self-supporting or twining,
50- 70 cm
high, sarmentose, runners warty.
Shoots
Perennial, herbaceous, basally slightly corky, sparsely covered with appressed,
180-200 µm
long trichomes, glabrescent; internodes
5-15 mm
long,
1-2 mm
diam.
Latex
Colourless, sparse.
Leaves
FIG. 5. ─
Marsdenia neocaledonica
Meve, Gâteblé & Liede
,
sp. nov.
:
A
, branch with inflorescences;
B
, leaf in cross-section;
C
, branch with open fruit;
D
, leaf in cross-section;
E
, flower in lateral view;
F,
gynostegium;
G
, pollinarium;
H
, style-head;
I
, seed. Drawings:
A
,
B
,
E -H
, U. Frensch from
H.S. MacKee 16662
;
C
,
D
,
I
,
H.S. MacKee 36874
(P). Scale bars: A, C, 2 cm; B, 5 mm; D, 7.5 mm; E, 1 mm; F, 0.5 mm; G, 0.2 mm.
With petiole
2-5 mm
long, densely and mostly distichously arranged, leaf blades coriaceous, with 2 colleters at the base, discolorous,
20-40 mm
long (leaves supporting lateral shoots to
120 mm
),
4-8 mm
wide, elliptic, basally rounded, apically obtuse and mucronate, marginally revolute, adaxially and abaxially glabrous.
Inflorescences
Always one per node, growth continued beyond inflorescence, 3-7(-15)-flowered, all flowers open synchronously, sciadioidal. Peduncles
3-6 mm
long, with sparse appressed trichomes,
180-200 µm
long.
Flowers
With floral bracts
c.
0.3 mm
long,
0.2 mm
wide at the base, ovate, with scattered trichomes. Pedicels
3-6 mm
long, sparsely covered over the whole surface with flexuous trichomes,
180-200 µm
long. Flower buds 20
×
15 mm
when mature, conical.
Calyx
Entirely free, ciliate; lobes
0.6-0.8 mm
long,
c.
0.5 mm
wide, ovate, apically acute.
Corolla
2-2.5 mm
long,
c.
4 mm
diam., campanulate-rotate, abaxially yellow to purple, adaxially yellow, adaxially with
100-150 µm
long trichomes concentrated on the tube and on the lateral parts of the lobes; lobes fused for about a third of total corolla length,
1-1.5 mm
wide, patent, ovate, apically acute.
Gynostegial corona of free staminal lobes
Glabrous,
0.5-0.7 mm
long, shorter than the gynostegium; lobes laminar, ovate, marginally thickened, apically recurved.
Gynostegium
0.9-1 mm
long,
0.9-1 mm
diam., elevated by a column of
350-400 µm
length; anthers broader than long, rectangular, abaxially planar; anther wings
300-350 µm
long, extending along the whole length of the anther; anther wings of adjacent anthers parallel to each other, in the same plane as the anther; connective appendages 375-400
×
300-350 µm
, triangular, narrower than the stamen, slightly inflexed.
Pollinarium
Corpusculum
c.
220 µm
long, more than twice as long as broad, elliptic, margins of the corpuscular cleft sinuate; caudicles
70- 100 µm
long, (sub-)basally inserted at the corpusculum, cylindrical, s-shaped, concave-convex, not thickened at the insertion of the pollinium; pollinia apically attached to the caudicles, erect, 250-270
×
60-80 µm
, ovate in cross-section, oblongoid.
Style-head
0.5-0.7 mm
long,
0.5-0.6 mm
diam., forming a nose at the upper end of the corpusculum; upper part
0.4-0.5 mm
long, longer than the lower part, conical.
Follicles
Always one per flower, 30-40 ×
6-8 mm
, obclavate, round in cross-section, acute, apically strongly beaked, wingless, medium brown, longitudinally grooved (when dry), glabrous, endocarp shining.
Seeds
6-6.5
×
3-3.5 mm
, ovate, medium brown; seta and aseta side smooth, marginally with
0.5-0.6 mm
wide wing with entire margin; coma
15-20 mm
long.
REMARKS
Vegetatively with the linear leaves and florally with details such as gynostegium, corona and pollinarium structure a close relationship between
M. neocaledonica
,
sp. nov.
and
M. mackeeorum
,
sp. nov.
and
M. microstoma
is indicated. However, with
4 cm
as maximum length, the leaves are shortest in
M. neocaledonica
, always surpassed in length in the other two species. The epithet “microstoma” indicates that the corolla of
M. microstoma
is urceolate (urn-shaped) and fused for more than half of its length, similar to the ovoid-urceolate corolla in
M. mackeeorum
,
sp. nov.
The corolla of
M. neocaledonica
,
sp. nov.
, however, is open and subcampanulate with the lobes fused for around one third of total corolla length. Finally, the corona of
M. neocaledonica
,
sp. nov.
is expanded to include interstaminal portions as well, a character missing in the other two species.