DSpace at VNU: Lysimachia vietnamensis and L. verbascifolia spp. nov. (Primulaceae) from Vietnam

Nordic Journal of Botany 29: 601Á604, 2011
doi: 10.1111/j.1756-1051.2011.01174.x,
# 2011 The Authors. Nordic Journal of Botany # 2011 Nordic Society Oikos
Subject Editor: Henrik Ærenlund Pedersen. Accepted 7 March 2011

Lysimachia vietnamensis and L. verbascifolia spp. nov. (Primulaceae)
from Vietnam
Phan Ke Loc and Hu Chi-Ming
P. K. Loc, Faculty of Biology, Hanoi Univ. of Science, Vietnam National Univ., Hanoi, Vietnam. Á C. M. Hu (), South
China Botanical Garden, the Chinese Academy of Sciences, CN-510650 Guangzhou, PR China.

Two new species of Lysimachia (Primulaceae), L. vietnamensis L. K. Phan & C. M. Hu and L. verbascifolia C. M. Hu &
K. L. Phan from Vietnam are described and illustrated.

During the past fifteen years a continuing program on
‘Biodiversity survey and plant conservation of Vietnam’ has
been carried out jointly by the ‘Vietnam botanical conservation program’, the Institute of Ecology and Biological
Resources (IEBR) of Vietnam, the Missouri Botanical
Garden (MBG), and with the participation of many
national and international institutions and organizations.
The field exploration site is located in northern Vietnam, a
hotspot of biodiversity in southeastern Asia, and more than
27 thousand collection numbers of higher vascular plants
have been collected. While identifying the species of the
genus Lysimachia, two new species growing in limestone
areas were found as described in this paper.
With respect to the floral structure, the two new species
clearly belong to subgenus Idiophyton Hand.-Mazz. with the
characters proposed by Chen and Hu (1979) and Hao et al.
(2004); basifixed anthers, much longer than the filaments
and usually open by apical pores. The genus as a whole is

almost cosmopolitan, but exhibits endemism. The subgenus
Idiophyton is presumed to be the most primitive group of
the genus, with its greatest concentration of species and
diversity confined to south Yunnan, Guizhou and Guangxi
in China, as well as northern Vietnam. In this area,
especially in the limestone hills, endemism is very high.
Both new species have a narrow distribution and occur as
isolated individuals in suitable habitats. Hu (1992) recognized fourteen species of Lysimachia in Vietnam, and
together with the two new taxa decsribed here, the number
of species has increased to sixteen.
Lysimachia vietnamensis L. K. Phan & C. M. Hu sp. nov.
(Fig. 1)
Species L. asperae Hand.-Mazz. in sectione Apodanthera
affinis, a qua floribus majoribus, pedicellis longioribus, lobis
calycis subulato-lanceolatis praeter alia signa distinguitur.

Type: Vietnam. Bac Kan Province: Na Ri District, Liem
Thuy Commune, hills east of Na Bo Village, ca 21857’N,
106805’E, ca 702 m a.s.l. 15 Jul 2004. Daniel E. Atha,
Nguyen Tien Hiep and Pham Van The DA4852 (holotype:
HN, isotype: NY, IBSC).
Perennial herb, 25Á40 cm tall. Stems erect, quadriangular,
ca 1.5 mm in diameter, more or less woody at base,
glabrous, much branched. Branches slender, 4Á30 cm long,
spreading or reclining, bearing abbreviated branchlets in
axils of leaves; branchlets 1Á4 mm, 2Á4-leaved. Leaves
alternate, papery, variable in size, those on stems and
branches broadly elliptic to orbicular-elliptic, 9Á15 )6Á10
mm, apex apiculate to shortly acuminate, base attenuate
into a 1Á4 mm long petiole, abaxial surface glabrous,

adaxial surface initially with a few appressed, bristle-like
hairs, glabrescent; margins ciliate, with short bristle-like
hairs, appearing minutely serrulate; lateral veins 2Á3 on
each side of midvein, obscure on both surfaces. Leaves on
abbreviated branchlets smaller, broadly ovate to suborbicular, 3.5Á7.0 )3Á5 mm. Flowers solitary, axillary;
pedicels very slender, 8Á12 mm long, longer than the
subtending leaves, glabrous, with a few minute and
scattered glands. Calyx ca 4.8 mm, divided nearly to the
base; lobes subulate-lanceolate, less than 0.5 mm broad at
the base, glabrous outside, sparsely and minutely glandular
inside. Corolla pale yellow, united in the lower 0.3Á0.5
mm; lobes narrowly lanceolate, 5.0Á5.5)1.0 mm, apex
acute, glabrous. Stamens adnate to the base of the corolla,
antepetalous; filaments ca 0.5 mm long, connate basally
into a ring and fused with corolla, free parts less than 0.2
mm long; anthers basifixed, linear-lanceolate, ca 3.5 mm
long, base sagittate, opening by apical pores. Ovary ovoid,
glabrous; style filiform, ca 4.8 mm long; stigma punctiform.

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Figure 1. Lysimachia vietnamensis L. K. Phan & C. M. Hu sp. nov. (A) habit, (B) flower, (C) calyx, (D) corolla opened up showing
stamens, (E) anther, (F) pistil.

Capsule globose-ovoid, 2.5Á3.0 mm in diameter, pale
brown, splitting in valves when mature.
Distribution, habitat and phenology

Lysimachia vietnamensis is so far known only from the type

locality on the hills east of Na Bo Village (ca 21857’N,
106805’E) in Liem Thuy Commune, Na Ri District, Bac
Kan Province, Vietnam. It grows on the margin of wet
evergreen broad-leaved forests at 700 m a.s.l., occurring as
isolated individuals on a rocky ridge composed of crystalline
marble-like highly eroded limestone. Flowering and fruiting
occur in July, the fertile structures represented by a
complete maturation sequence ranging from immature
buds to ripe fruits.
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Similar species

Lysimachia vietnamensis closely resembles L. aspera Hand.Mazz., a species endemic to Guangxi, China, but is easily
distinguished by its longer pedicels, larger flowers, and
linear-lanceolate calyx-lobes (Chen and Hu 1979, 1989, Hu
and Kelso 1996).
Lysimachia verbascifolia C. M. Hu & L. K. Phan sp. nov.
(Fig. 2)
Inter species descriptas tantum cum L. pilosa Fletcher et L.
grandifolia Hemsl. comparanda, a quibus floribus in axillis
foliorum congestorum solitariis, pedicellis multo longioribus
inter alia recedit.
Type: Vietnam. Thanh Hoa Province: Quan Hoa District,
Phu Le Commune, Hang Village, around point


Figure 2. Lysimachia verbasifolia C. M. Hu & L. K. Phan sp. nov. (A) habit, (B) calyx, (C) corolla opened up showing stamens, (D)
anthers showing dorsal and ventral surfaces, (E) pistil.

21831’32’’N, 105804’54’’E, 350Á500 m a.s.l. 18 Aug 2010,
Phan Ke Loc and Ha Van Dan P 10982 (holotype: HN,
isotype: IBSC, MO, LE).
Perennial herbs; stems erect from a geniculate base, 4Á10
cm tall, 3Á5 mm in diameter,9woody at base, unbranched,
villous. Leaves alternate, usually 4Á8 mm apart, the upper
4Á6 leaves crowded at apex of stem, apperaing subverticillate; petioles 3Á6 cm long, grayish villous; leaf blade
elliptic to broadly elliptic, 7Á17 )3.5Á8.0 cm, base broadly
cuneate, apex obtuse, margin entire, ciliate, grayish villous
on both surfaces, initially very densely hairy, but becoming
sparser on adult leaves; lateral veins 6Á8 on each side of
midvein, densely grayish villous. Flowers subumbellate, 4 to
many crowded in a terminal leaf-whorl; pedicels slender,
unequal, 1Á4 cm long, elongating to 4Á7 cm in fruit, pilose;
in the next growing season the growth of the stem continues
apically by forming a new leaf whorl, then the fruiting
pedicels become axillary in leaf scars or remaining leaves

under the terminal leaf whorl. Calyx ca 9 mm long, divided
nearly to the base; lobes lanceolate, 9)2 mm, 5-veined,
sparsely pilose outside. Corolla pale yellow, divided nearly
to the base; lobes oblong-lanceolate, 11.0Á12.0 )3.5 mm,
apex acute. Stamens 5; filaments slender, connate basally
into a ring, free parts ca 3 mm long; anthers ca 5 mm long,
gradually narrowed upward from a cordate base, basifixed,
opening by apical pores. Capsule globose, ca 5 mm in
diameter, pale brown, splitting in valves when mature;
persistent style slender, 8Á9 mm long.
Distribution, habitat and phenology

Lysimachia verbascifolia is so far only known from the type
locality on the hills of Hang Village (21831’32’’N,
105804’54’’E), in Quan Hoa District, Thanh Hoa Province, Vietnam and one locality nearby. It is a lithophytic
herb, growing clustered in small groups in disturbed
primary evergreen seasonal broad-leaved lowland forest,
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on very steep rocky slopes and cliffs composed of crystalline
marble-like highly eroded limestone at about 350Á650 m
a.s.l. Flowering occurs in JulÁOct, fruiting in DecÁMar.

Acknowledgements Á The authors thank the Vietnam Botanical
Conservation Program, Ministry of Science and Technology,
Vietnam, National Science Foundation USA and Fauna and Flora
International, Indochina Program for funding the field trips, and
thanks also to Mrs Liu Yun-xiao for the excellent line drawings.

Similar species

Lysimachia verbascifolia is quite distinct from all species
known to us in subgenus Idiophyton; its morphological
affinity is with L. grandifolia Hemsl. and L. pilosa Fletcher,
but it is easily distinguished by its solitary flowers clustered
in the axils of subterminal leaves (not forming peduncled
umbels or corymbs) and longer pedicels (Chen and Hu
1979, 1989, Hu and Kelso 1996, Hu 1999).
Additional specimens examined

Vietnam. Thanh Hoa Province: Quan Hoa District, Phu Le

Commune, Hang Village, around point 20831?13??N,
105805?45??E, 450Á650 m a.s.l., 3 Oct 2003, Leonid
Averyanov, Phan Ke Loc and Nguyen Tien Vinh HAL
3788 (HN, IBSC); the same locality as type specimens,
around point 20831’32’’N, 105804’54’’E, ca 350Á500 m
a.s.l., 9 Apr 2010, Phan Ke Loc, Ha Van Luc and Ha Van
Nhuan P 10935 (HN, IBGC).

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