Novelties from the Northern Mountains Complex of Madagascar V: A new threatened Pandanus (Pandanaceae) from the Kalobinono massif
Author
Callmander, Martin W.
Conservatoire et Jardin botaniques de la Ville de Genève, ch. de l’Impératrice 1, C. P. 71, 1292 Chambésy, Switzerland.
martin.callmander@ville-ge.ch
Author
Razakamalala, Richard
Missouri Botanical Garden, B. P. 3391, Antananarivo 101, Madagascar.
Author
Luino, Iacopo
Conservatoire et Jardin botaniques de la Ville de Genève, ch. de l’Impératrice 1, C. P. 71, 1292 Chambésy, Switzerland.
Author
Andriamarisoa, Roger Lala
Missouri Botanical Garden, B. P. 3391, Antananarivo 101, Madagascar.
Author
Buerki, Sven
Department of Biological Sciences, Boise State University, Boise, ID 83725, USA.
text
Candollea
2020
2020-05-12
75
1
99
105
journal article
20452
10.15553/c2020v751a10
ba005072-8bee-408b-8661-c5e0bd6ad719
2235-3658
5724834
Pandanus kalobinonensis
Callm., Razakamal. & Luino
,
sp. nov.
(
Fig. 2
,
3
).
Holotypus
:
MADAGASCAR
. Reg. DIANA [Prov.
Antsiranana
]:
Fkt. Anketrabe-Belinta
,
massif du Kalobinono
,
13°38'42"S
48°40'29"E
,
740 m
,
16.X.2015
, fr.,
Luino
&
Razakamalala
106
(
G
[
G00341880
]!; iso-: TAN!)
.
Haec species ab omnibus congeneris syncarpio parvo globoso solitario brevipedunculato atque drupis monocarpellatis in stigma spiniforme adaxialiter sulcatum desinentibus differt.
Treelet
to
3–4 m
tall; stem prickly, up to
5 cm
dbh.
Leaves
125–160 cm
long,
2–3 cm
wide in the middle,
3 cm
wide near the sheath, gradually attenuate in the upper third, and tapering to a flagellate apex in the distal
5 cm
, coriaceous; longitudinal and transverse veins visible on both surfaces; prickles white
in vivo
; marginal prickles beginning at (4–)
5–6 cm
above the base and extending to the apex, antrorse,
2–4 mm
and placed
2–8 mm
apart in the lower third, to
2 mm
and
5–10 mm
apart in the middle third; to <
1 mm
and
2– 4 mm
apart in the distal third; midrib armed below in the upper 2/3, prickles small (<
1 mm
), irregularly disposed (
5–10 mm
); sheath
5 cm
long, c.
3.5 cm
wide at apex c.
4–4.5 cm
large at base.
Infrutescence
terminal, a solitary syncarp subtended by naviculate bracts, borne on a straight short peduncle; syncarp 50 ×
60–70 mm
, globose to ovoïd; peduncle straight, short,
65 mm
long, c.
9 mm
in diam at apex, trigonous, 3– 4 remaining bracts, c.
5– 7.5 cm
long, positioned near the base of the syncarp, boat-shaped at base and becoming flagellate in the distal part.
Fig. 1. –
The Galoko mountain range with the Galoko summit on the left, the distinctly shaped domes of the Kalobinono on the right and rice plantations in the foothills. [Photo: S. Wohlhauser]
Drupes
c. 65–140 per syncarp, (15–)20(–25) mm high,
5–7 mm
wide, (3–)
4–6 mm
thick, 4–6 angled; carpel 1, free in the upper fourth, tapering to the base; pileus pyramidal, somewhat rounded at apex.
Stigma
1, erect or curved, spiniform, on the centre of the apical face of the pileus, brown
in vivo
,
3–5 mm
in length, stigmatic groove abaxial, covering c. 2/3 of the length of the stigma.
Endocarp
10–13 mm
long in the centre, <
1 mm
wide,
4–6 mm
away from stigma base; seed locule oblong, 10 – 12 ×
3– 5 mm
, superior and inferior mesocarp fibrous.
Staminate
plant unknown.
Etymology.
– The species epithet refers to the Kalobinono massif and its eroded landscape of Isalo Sandstone dominated by a pair of distinctly shaped domes (fig. 1). The literal translation from the Sakalava dialect means “princess with large breasts”. Similarly, the name Galoko refers to a local king. The two summits are sacred for the local Sakalava. According to the legend, the queen embodied in the Kalobinono massif gave birth to the nearby Manongarivo massif, fathered by the king at Galoko (SOLO et al., 2008).
Distribution and ecology. –
Pandanus kalobinonensis
is currently only known from the lowland moist evergreen forest in the Kalobinono massif (northwestern
Madagascar
) between
420 to 740 m
elevation.
Conservation status. –
Pandanus kalobinonensis
is known from 2 locations from the Galoko-Kalobinono Protected Area collected at a distance of c.
1 km
in lowland moist evergreen forests. The
holotype
collection is located well within the intact forest at
740 m
, but the
paratype
is located at
425 m
and was made only a hundred meters from recently cleared forest. This latter location could be projected to disappear in a relatively near future. Lowland moist evergreen forests were highly threatened in the
Fig. 2. –
Pandanus kalobinonensis
Callm., Razakamal. & Luino.
A.
Fruiting
branch;
B.
Detail of the syncarp;
C.
Drupe;
D.
Cross section of a drupe;
E.
Basal section of a leaf;
F.
Mid section of a leaf;
G.
Apex section of a leaf. [
A–D:
Razakamalala et al. 7586
, TAN;
E–G:
Luino & Razakamalala 106
, TAN] [Drawing: R.L. Andriamiarisoa]
Fig. 3. –
Photograph of
Pandanus kalobinonensis
Callm., Razakamal. & Luino.
[
Luino & Razakamalala et al. 106
] [Photo: I. Luino]
massifs where Tsimihety immigrants have established settlements for several decades and are practicing slash and burn agriculture (SOLO et al., 2008) (
Fig. 1
). The loss of moist evergreen forest area between 2006 to 2016 has reached 1408 ha, which represents 15% of the total cover of the PA (RABENANDRASANA et al., 2018). Since mid 2018, slash and burn agriculture is restricted within the strict conservation zone, but the risk of uncontrolled pasture fire is still a threat (P. Ranirison, pers. comm.). With an area of occupancy (AOO) of
4 km
², and despite that both collections ocur within limits of the protected area,
P. kalobinonensis
is therefore assigned a preliminary conservation status of “Endangered” [EN B1ab(ii,iii,iv,v)+2ab(ii,iii,iv,v)] using IUCN Red List Categories and Criteria (
IUCN, 2012
).
Notes. –
Pandanus kalobinonensis
is morphologically distinct among Malagasy species of
Pandanus
. Its small globose solitary syncarp bearing monocarpellate drupes topped by a spiniform stigma (
Fig. 2
,
3
) resembles several Southeast Asian
Pandanus
species.
Several species in
Madagascar
were hypothesized to have morphological Indo-Malaysian affinities (STONE 1974; CALLMANDER & LAIVAO, 2003).
Pandanus platyphyllus
Martelli
was for example placed by STONE (1974) in the Malaysian
Pandanus
subgenus
Rykia
(Vrise) B.C. Stone
before staminate plants were studied by
HUYNH (1977)
and confirmed to belong to the Afro-Malagasy subgenus
Vinsonia
(Warb.) B.C. Stone.
Phylogenetic analyses further demonstrated that those latter morphological affinities were most likely the result of convergent evolution since all Malagasy species of
Pandanus
subgenus
Vinsonia
formed a monophyletic clade (
BUERKI et al., 2012
). In this context,
Pandanus kalobinonensis
is therefore classified in
Pandanus
subgenus
Vinsonia
. The sectional placement of this species remains to be established, like other recently discovered morphologically isolated species in
Madagascar
(see
CALLMANDER et al., 2008
,
2009b
,
2013
).
Paratypus
. –
MADAGASCAR
. Reg. DIANA [Prov.
Antsiranana
]:
Beramanja
,
Anketrabe Belinta
,
massif du Kalobinono
,
13°38'16"S
48°40'21"E
,
425 m
,
29.IX.2013
, fr.,
Razakamalala et al.
7586
(TAN)
.