The Lauraceae Juss. of Indo-China: fifteen new species, four new combinations and two neotypifications
Author
De Kok, Rogier P. J.
text
Adansonia
2023
3
2023-01-09
45
1
1
25
journal article
10.5252/adansonia2023v45a1
1639-4798
7522473
11.
Litsea rubrobrunnea
de Kok
,
sp. nov.
(
Figs 11
;
12
)
DIAGNOSIS. — This species differs from its close relative
Litsea monopetala
(Roxb.) Pers.
by having leaves with an acute apex and 10-13 pairs of secondary nerves (while
L. monopetala
has leaves with an obtuse acute to acuminate apex and 6-11 pairs of secondary nerves); petioles which are swollen and
8-11 mm
long (while
L. monopetala
has petioles which are slender and
10-25 mm
long). —
TYPE
SPECIMEN. — [
Vietnam
] près
Tourane
,
16°4’18.372”N
,
108°9’1.368”E
,
10.VIII.1923
,
Poilane
7829
(holo-,
P
[
P01976151
]).
DISTRIBUTION. — Vietnam (see
Fig. 12
).
ECOLOGY. — Growing in lowland and mountain forest, sometimes over limestone, between
500-1800 m
altitude. Flowering between December to April; fruiting from August to March.
CONSERVATION ASSESSMENT. — Vulnerable (VU B2ab(ii,iii)). This species is only known from six localities. An analysis of the Extent of Occurrence (EOO) gives an assessment of Least Concern and the Area of Occupancy (AOO) suggests an IUCN Conservation Assessment of Vulnerable. Given that it is known from only six populations and has small area of occupancy as well as the intensive logging and landscape modification that has occurred in the region during the last 50 years, this species must be considered Vulnerable.
ADDITIONAL COLLECTIONS SEEN. —
Vietnam
.
Thua Thien-Hue
:
Nui Back Ma
, près
de Hu
ế,
16°10’0.984”N
,
107°49’58.008”E
,
20.IV.1939
,
Poilane
29853
(
P02132127
)
;
Quang Tri
:
Massif de Dong Che
,
16°37’58.8”N
,
106°55’58.8”E
,
22.VIII.1924
,
Poilane
11271
(
P02132139
)
;
Quang Nam
: près de village
Moi de Go-oi
,
24.II.1941
,
Poilane
31548
(
P
)
;
Đà N
ẵng: Ba-Na, près
Tourane
,
11°22’39.648”N
,
108°50’36.996”E
,
27.II.1939
,
Poilane
29117
(
P02035874
)
;
Lào Cai
: village
de Tien Chua
, nord de
Lai Chau
,
22°24’51.732”N
,
103°26’57.264”E
,
12.IV.1936
,
Poilane
25728
(
P01976047
)
.
DESCRIPTION
Tree
5-10 m
tall, dbh
10-33 cm
. Twigs slender
2.6-4.2 mm
thick, rounded in cross-section, sparsely hairy when young, glabrescent; hairs yellowish, appressed; terminal leaf bud ovoid,
c.
2 mm
long, apex acute, velutinous. Leaves alternate, drying brown reddish; blade elliptic to lanceolate, 12-16 ×
4.5-6 cm
, apex acute, base cuneate, blade leathery, penninerved, secondary nerves 10-13 pairs, curved near margin and brochidodromous, tertiary nerves scalariformreticulate; upper surface glabrous, sometimes densely hairy on midrib, midrib and secondary nerves sunken, tertiary nerves distinct; lower surface sparsely hairy, often more densely hairy on major veins, midrib and secondary nerves raised, tertiary nerves distinct; petiole half-terete,
8-11 mm
long, swollen, densely hairy.
FIG. 10. — Plate of
Litsea nhatrangensis
de Kok
,
sp. nov.
:
A
, twig with leaves;
B
, infructescence with fruit;
C
, detail of leaf under surface. All from
Poilane 5019
(P04456803). Drawing by Giulia Iaconelli. Scale bars: A, 5 cm; B, 2 cm; C, 1 cm.
FIG. 11. — Plate of
Listea rubrobrunnea
de Kok
,
sp. nov.
:
A
, twig with leaves and infructescence;
B
, infructescence with fruit;
C
, detail of leaf under surface. All from
Poilane 29117
(P02035874). Drawing by Giulia Iaconelli. Scale bars: A, 4 cm; B, 2 cm; C, 1.5 cm.
FIG. 12. — Distribution of
Litsea rubrobrunnea
de Kok
,
sp. nov.
(),
Litsea salmonea
A.Chev. ex de Kok
,
sp. nov.
(),
Machilus coriacea
A.Chev. ex de Kok
,
sp. nov.
(),
Neocinnamomum huongsonensis
Kim Dao
,
sp. nov.
() and
Phoebe petelotii
Kosterm. ex de Kok
,
sp. nov.
().
Inflorescences in leaf axils,
4-8 mm
long, in clusters of umbels, glabrous to sparsely hairy; hairs yellowish, appressed. Flowers unknown.
Fruit ellipsoid, 14-18 ×
6.5-9.7 mm
, apex rounded, smooth, glabrous;cupule woody,4.5-5×
2.9-4mm
,margin entire,glabrous, surface warty; stalk not swollen,
c.
2.3 mm
thick (see
Fig. 11
).
NOTES
Flowers are unknown for this new species, which is problematic for its generic placement. However, its other characters fit morphologically (like the inflorescence shape and cupule) very well in
Litsea
,
and I have decided to place it here.