Taxonomic revision of Causonis (Vitaceae) in New Guinea
Author
Trias-Blasi, Anna
Author
Dee, R.
Author
Jimbo, Tiberius
Author
Jackes, Betsy
Author
Parmar, Gaurav
text
Edinburgh Journal of Botany
2022
2022-06-14
79
1895
1
10
http://dx.doi.org/10.24823/ejb.2022.1895
journal article
10.24823/EJB.2022.1895
1747-0036
12521478
2.
Causonis maritima
(Jackes) Jackes, Telopea
23: 70 (2020)
.
Cayratia maritima
Jackes, Austrobaileya
2(4): 366 (1987)
. –
Type
:
Australia
,
Queensland
,
Cook
,
Lakefield National Park
,
9.3 km
north of
Ranger’s Cottage
,
15.116°S
,
144.316°E
,
26 vi 1982
,
Jackes,
B
.
R
. s.n.
(
holotype
BRI
[barcode
AQ0441384
];
isotypes
A
[barcode 00051579],
CANB
[barcodes
CANB 375543.1
,
CANB 375543.3
,
CANB 375544.2
,
CANB 375544.4
], DNA [barcode DNA D0056167],
K
! [barcode
K000072595
],
L
! [barcodes
L
. 0763085,
L
. 0763086],
MEL
[barcode
MEL 1582485
A
],
NSW
[barcode
NSW 830674
,
NSW 171693
])
.
Herbaceous climber.
Stem
angular,
2–4 mm
in diameter, very branched, usually glabrous with simple hairs at nodes when young; tendril 3-furcate (occasionally 2-furcate), slender, wiry, leaf-opposed, cylindrical, with a non-coiling section followed by coiling section,
1.5–14 cm
long, glabrous, lacking adhesive discs at the tips.
Leaves
compound, 3-foliolate, alternate; petiole
1–8 cm
long, hairy as on stem, central petiolule
0.5–2.5 cm
long, lateral petiolules
1–8 mm
long, hooked hairs sometimes present; central leaflet blade ovate to rhomboid, 1–10 ×
1–7 cm
, base cuneate to rounded; lateral leaflet blade 2–8 ×
2–6 cm
, base oblique; margin dentate to crenulose, apex acute; adaxial surface almost glabrous at maturity except for the presence of uniseriate 3- to 14-celled hooked hairs on the midrib, abaxial side usually glabrous, occasionally with hooked hairs at the junction of the petiole and the lamina; veins inconspicuous.
Inflorescence
a ramified, axillary, mostly dividing dichotomously, corymbose, compound dichasium,
2–12 cm
long; peduncle
1.5–16 cm
long, hairy as on leaf to glabrous, pedicels
1–3 mm
long, papillose.
Buds
ovoid, 1.25–2 ×
1–2 mm
.
Calyx
cupuliform, entire, margin sinuate, 0.5–0.75 ×
1.5–2 mm
, papillose.
Corolla
petals 4, ovate, 1.25–2.25 ×
1–2 mm
, apex cucullate, papillose.
Stamens
4; filaments flattened, broadening at the base,
0.5–1 mm
long; anthers orbicular, medifixed,
0.4–0.75 mm
long.
Ovary
adnate to the disc; disc with 4 lobes, glabrous.
Style
conical, slender,
0.5–1 mm
long; stigma inconspicuous.
Fruit
a berry, subglobose,
0.5–1.25 mm
in diameter, glabrous, smooth, base attenuate.
Seeds
2–4, triangular-obovoid, 5–7 ×
4–7 mm
, ventral infolds side conspicuous with 2 keels to cup-shaped cavities, dorsal side convex with a linear chalazal knot, endosperm nearly T-shaped in cross-section. See
Figure 2A, F–H
.
Distribution
.
Australia
,
Brunei
,
China
,
India
,
Indonesia
(Borneo, New
Guinea
, Sulawesi),
Malaysia
,
Moluccas
Islands,
Papua New Guinea
,
Singapore
,
Solomon Islands
and
Vietnam
.
Distribution in New
Guinea
.
Indonesia
(
Irian Jaya
) and
Papua New Guinea
(Autonomous Region of Boubainville,
Milne Bay
) (see
Figure 1
).
Habitat and ecology
. Coastal, alluvial or sandy soil, swamps, forest edge, regrowth; near sea level to
3500 m
.
Figure 2.
Distinctive characters in New Guinea
Causonis
. A and B, Tendrils: A,
Causonis maritima
;
B,
C. trifolia
(adapted from
Jackes, 1987
). C–H, Seeds: C–E,
Causonis trifolia
(C, cross-section; D, ventral view; E, dorsal view); F–H,
Causonis maritima
(F, cross-section; G, ventral view; H, dorsal view). Drawn by A. Trias-Blasi.
Phenology
. Flowering and fruiting throughout the year.
Proposed IUCN conservation category
.
Causonis maritima
is distributed from
India
and
China
to North
Australia
with no apparent threats, and therefore it can be treated as Least Concern (LC). In New
Guinea
, although we only have four collections, the EOO is calculated to be
676,693 km
2
, and therefore it is also considered to be Least Concern (LC).
Additional specimens examined
.
INDONESIA
.
Irian Jaya
:
Snow Mountains
[Maoke Mountains]:
Bernhard Camp Idenburg River
[Taritatu river],
3°40′S
,
140°15′E
,
iv 1939
,
Brass
13947 (
K
[
K000871696
],
L
[
L
.2329267]).
NW New Guinea
,
Pionier
bivouac,
vi 1926
,
Docters van Leeuwen
9362 (
BO
[2 duplicates],
K
[
K000871697
])
.
PAPUA NEW GUINEA
.
Autonomous Region of
Bougainville
province:
SW of Toiumonapu Plantation
,
6°10′S
,
155°20′E
,
2 vii 1963
,
van Royen
NGF16418 (
BO
,
K
[
K000871707
],
L
[
L
.2329188]).
Milne Bay
province
: Subdist Alotau,
Haumo River
,
3 miles
out of Alotau on road to Gurney
2 miles
east of
Rabe village
,
10°20′S
,
150°25′E
,
21 iii 1976
,
Larivita
LAE70553
(
K
[
K000871688
; sheet 2])
.