全 文 ：Journal of Systematics and Evolution 46 (2): 220–225 (2008) doi: 10.3724/SP.J.1002.2008.07021
(formerly Acta Phytotaxonomica Sinica) http://www.plantsystematics.com
Mussaenda lancipetala X. F. Deng & D. X. Zhang, a new species
of Rubiaceae from China
1,2Xiao-Fang DENG 1Dian-Xiang ZHANG*
1(South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, China)
2(Institute of Agro-Environmental Protection, Ministry of Agriculture of China, Tianjin 300191, China)
Abstract Mussaenda lancipetala X. F. Deng & D. X. Zhang, a new species of Rubiaceae from Yunnan Prov-
ince, Southwestern China, is described and illustrated. The new species is characterized by its reverse herkoga-
mous sexual system, its ovate-lanceolate corolla lobes with caudate apex, and corolla tube covered with sparse
farinose pubescence, by which it is clearly distinguished from other species of Mussaenda.
Key words Mussaenda, Mussaenda lancipetala X. F. Deng & D. X. Zhang, new species, pollen morphology,
sexual system, taxonomy.

Mussaenda L. s.s. is a paleotropical genus of ca.
132 species (Alejandro et al., 2005), with ca. 30
species occurring in China (Hsue & Wu, 1999). Spe-
cies in Mussaenda are characterized by having
enlarged petaloid calyx lobes, valvate-reduplicate
aestivation of the corolla lobes and indehiscent,
berry-like fruits, and the woody, scandent or liana
habit.
The generic circumscriptions have always been
controversial since the genus was established (Bremer
& Thulin, 1998; Huysmans et al., 1998; Puff et al.,
1993; Robbrecht, 1988; Li, 1943; Wernham, 1916). A
recent molecular phylogenetic analysis based on ITS
and trnT-F sequences revealed that the genus in its
broad sense is polyphyletic, although the Asian species
together form a monophyletic clade (Alejandro et al.,
2005).
In order to revise the Chinese Mussaenda, we
have carried out extensive field work in Yunnan
Province. Among a large number of Mussaenda
collections, one of them was not in accordance with
any of the known species recorded in China and
neighboring Asian countries based on the observation
to its gross morphology, habit and habitat in the field,
SEM observation of pollen morphology, and LM and
SEM observation of leaf epidermal characters. The
proposed new species, M. lancipetala, presents a
superficial resemblance to M. roxburghii Hook. f. in
having ovate-lanceolate corolla lobes with filiform tips,
but differs in having adaxially glabrous leaves, with
11–13 pairs of secondary veins and farinose pubes-
cence out of the corolla tube. The pollen and leaf
epidermal morphology, gross morphology of the
species is different from the known taxa, and a new
species, M. lancipetala, was eventually proposed.
1 Material and Methods
Field studies were undertaken by the authors in
2005 and also in 2006 in Yunnan Province, China, and
specimens from HITBC, IBSC, KUN and PE and
other main herbaria in Europe were examined. The
measurements and other details given in the descrip-
tion are based on field study as well as herbarium
specimen measurements.
Pollen material was collected in the field in Yun-
nan (vouchers were deposited in IBSC), as well as
from the herbarium of Kunming Institute of Botany,
Chinese Academy of Sciences (KUN), and all material
used in leaf epidermal observation were sampled from
the herbaria KUN and IBSC (see Appendix for a list of
specimens examined).
Dried pollen was acetolysed (fresh pollen was not
acetolysed) following Erdtman (1969), then suspended
in 70% ethyl alcohol after washed, air dried on brass
stubs and coated with gold palladium, and observed
under a JSM-6360LV scanning electron microscope.
Twenty pollen grains per sample were measured.
The samples for leaf epidermal observation were
treated for both light (LM) and scanning electron
microscopy (SEM). Samples were taken from fully
expanded mature leaves. For LM, the samples were
boiled in water for 20 min, then macerated in NaOCl
solution. Pieces of leaf epidermis were stained with a
solution of safranine, then dehydrated through an

———————————
Received: 5 Feburary 2007 Accepted: 30 September 2007
* Author for correspondence. E-mail: .
DENG & ZHANG: Mussaenda lancipetala, a new species of Rubiaceae from China

221
alcohol series and washed with xylene before mounted
in neutral gum, and then photographed with OLYM-
PUS AX 70. For SEM, the samples were clarified
using absolute alcohol, air dried, and then sputtered
with gold palladium, and examined and photographed
with JSM-6360LV.
2 Results and Discussion
2.1 Morphological observation
At first glance M. lancipetala somewhat resem-
bles M. roxburghii in leaf and flower shape. Never-
theless, upon careful examination of the specimens it
is clear that they are different species. Mussaenda
lancipetala has 11–13 pairs of secondary veins (vs.
only 7–9 pairs in M. roxburghii), 2.5–3.0 cm long
corolla tubes, with sparse pallid farinose hairs abaxi-
ally (vs. ca. 1.8–2.3 cm long corolla tubes with
densely adpressed primrose villose abaxially in M.
roxburghii) and the leaves glabrous on the adaxial
surfaces (vs. sparse short pallid pubescence in M.
roxburghii) (Table 1).
In addition, field observations indicated that M.
lancipetala have reverse herkogamous flowers (4
population for sampling). The flowers of M. lanci-
petala were hermaphrodite, monomorphic, with only
short-styled flower morph present in the populations
observed. We are not certain about the sexual system
of M. roxburghii, which is morphologically heterosty-
lous though.
2.2 SEM observation
Pollen and leaf samples of the two species of
Mussaenda, viz., M. roxburghii, and the species
described here, were examined under SEM. The
pollen grains of both species are single, isopolar,
radially symmetrical, small-sized, suboblate or sub-
spheroidal, and 4-colporate. However there is a con-
siderable variation in the size of pollen grains, exine
ornamentation and characters of apertures between the
new species and its ally (Table 2). In M. lancipetala
the pollen is subspheroidal in shape, the exine orna-
mentation is finely rugulose, and the colpus membrane
is sparely and finely granulate (Fig. 1: A), while in M.
roxburghii the exine ornamentation of pollen grains is
roughly rugulose with perforate, and the colpus mem-
brane is granulate (Fig. 1: C).
In a preliminary observation of the indumentum
and stomata of the investigated species, we found that
stomata occur only on the lower epidermis, and
trichomes and stomata in the leaf are not evenly
distributed (Fig. 1). Generally the hairs along the veins
are slightly denser and longer than those on the in-
ter-vein areas of the leaves. The ornamentation of
cuticular membrane (Fig. 1: I) and trichome, the
density of trichome and stomata, along with the size of
stomata are different between our new taxon and its
ally, and the results of the observations are shown in
Table 3.

Table 1 Diagnostic morphological characters of Mussaenda lancipetala and M. roxburghii
Character M. lancipetala M. roxburghii
Leaf trichome
Leaf size (cm)
glabrous adaxially; sparse white pubescent abaxially
15–24 × 6–8
sparse appressed pubescent adaxially; gray pubescent abaxially
10–12 × 3.5–5
2° veins 11–13 pairs 7–9 pairs
Inflorescence slightly diffuse pleiochasium slightly compacted pleiochasium
Semaphylls 6–7.5 × 4–5 cm 4.5 × 2 cm
Calyx lobe 10–12 mm long 5 mm long
Corolla tube 2.5–3.0 cm long, with sparse pallid farinose pubescent
abaxially
1.8–2.3 cm long, with dense adpressed primrose villose
abaxially
Corolla lobes (mm) 7–8 × 2.5–3.0 4–6 × 1.5–2


Table 2 Pollen characters of Mussaenda lancipetala and M. roxburghii
Character M. lancipetala M. roxburghii
Pollen shape subspheroidal subspheroidal
Pollen size (µm) 14.7 (11.3–17.0) × 15.6 (12.6–17.3) 14.4 (13.5–18.0) × 16.1 (14.4–20.0)
Polar view circular quadrivalve-circular
Aperture type 4-colporate 4-colporate
Colpus sculpture sparely finely granulate coarse granulate
Endoaperture shape round, with thickened margin round, with thickened margin
Ornamentation finely rugulose roughly rugulose with foveolatus
Journal of Systematics and Evolution Vol. 46 No. 2 2008 222


















































Fig. 1. A–C, SEM photomicrographs of pollen grains of two taxa of Mussaenda. A. M. lancipetala. Polar view. B. M. lancipetala. Polar view
showing exine ornamentation. C. M. roxburghii. Equatorial view showing colporate aperture. D–I, SEM and LM photomicrographs of leaf epider-
mis of two taxa of Mussaenda. D. M. lancipetala. A stoma. E. M. roxburghii. A stoma. F. LM micrographs of leaf epidermis of M. lancipetala.
Abaxial surface with stomata. G. M. roxburghii. Hair on abaxial surface showing ornamentation. H. M. lancipetala. Hair on abaxial surface showing
ornamentation. I. M. lancipetala. Adaxial cuticular membrane.
Scale bars: A, E=5 µm; B, C=1 µm; D, G, H=10 µm; F=50 µm; I=2 µm.


The veins and adaxial side of leaves of M. lanci-
petala are glabrous, while on M. roxburghii, there are
sparse, short and straight pubescences. Although on
the veins and abaxial side of leaves of both M. lanci-
petala and M. roxburghii there are sparse, short and
straight pubescences, the ornamentation of the hair
surface is different: the former is short striate (Fig. 1:
H) while the latter is papillate striate (Fig. 1: G). M.
lancipetala has much bigger and denser stomata than
M. roxburghii on the leaves.
DENG & ZHANG: Mussaenda lancipetala, a new species of Rubiaceae from China

223
Table 3 Leaf epidermal characters of Mussaenda lancipetala and M. roxburghii
Upper epidermis Lower epidermis Taxa
Cuticular
membrane
Trichome Stomatal size Stomatal density
(No./mm2)
Inner margin of
outer stomatal ledge
Cuticular
membrane
Trichome
M. lancipetala crass-scaly absent 24.9 (18.9–28.6) ×
14.8 (13.3–15.3)
555 smooth smooth sparse, with
striate orna-
mentation
M. roxburghii undulate-
striate
sparse, with
striate
ornamentation
20.0 (16.2–26.2) ×
14.3 (11.5–14.8)
273 smooth smooth sparse, with
papillate striate
ornamentation


2.3 LM observation
Under LM, the epidermal cell of these two spe-
cies is irregular polygonal and the pattern of anticlinal
walls are straight. The stomatal apparatuses of the
investigated species are nearly identical, belonging to
the paracytic type, occurring only on the lower epi-
dermis (Fig. 1: F).
According to our observations based on morpho-
logical analysis, LM and SEM observation, there are
very obvious differences among these investigated
species, and the specific status of M. lancipetala is
thus warranted.
3 Taxonomic treatment
Mussaenda lancipetala X. F. Deng & D. X. Zhang,
sp. nov. Fig. 2.
狭瓣玉叶金花
Species M. roxburghii Hook. f. affinis, sed foliis
supra subglabris; corollae tubis 2.5–3.0 cm longis,
lobis 5 angustioribus ovato-lanceolatis, 7 mm longis
differt.
Shrubs 2–4 m high, young branches angulate,
with sparse, grayish white pubescent, gradually gla-
brescent, terete when old. Leaves opposite, charta-
ceous, oblong or elliptic, 15–24×6–8 cm, margin
entire, apex acuminate, base cuneate, glabrous adaxi-
ally, sparse white pubescent abaxially; midrib and
veins with white pubescent sparse adaxially, dense
abaxially; secondary veins 11–13 pairs, arc ascending,
prominent beneath; petiole 1.0–3.0 cm long, with
sparse white pubescent; stipule triangular-lanceolate,
dense pallid villose in the middle, 8 mm long, bifid,
lobe lanceolate. Inflorescences pleiochasium, terminal,
peduncle ca. 3.0 cm long, flowers dense, pedicel 1 mm
long; bract trifid or bifid, the middle longest lobe up to
1 cm, bracteole lanceolate, 4–7 mm long; densely
white pubescent; hermaphrodite, reverse herkogamous;
calyx tube 3×2 mm, elliptic-turbinate, sparse grayish
white pubescent, calyx lobes 5, lanceolate, 1.0–1.2 cm
long, 1 mm wide at the base, densely grayish white
pubescent outside, semaphylls white, glabrous, ovoid,
6–7.5×4–5 cm, apex acuminate, base gradually an-
gustate, longitudinal veins 5, dense pubescent, stipe
2.5–3 cm long, densely pubescent. Corolla tube
2.5–3.0 cm long, ampliate from the middle, narrow
part 1 mm in diameter, ampliate part 2.5 mm in di-
ameter, with sparse pallid farinose hairs outside, inside
densely yellow clavillose villous at amplification,
thinly yellow pubescent below, corolla lobes 7–8 mm
long, ovate-lanceolate, tip caudate, with sparse fari-
nose hairs outside, densely yellow-papillate inside.
Stamens 5, inserted in middle of the corolla, filament
glabrous, 5 mm long, anther linear, 5 mm long. Style
glabrous, 1.2-1.5 cm long, stigma bifid-lamella equal,
glabrous, lamella oblong, 3 mm long; long-styled
flower not observed. Immature berry elliptic, 8×4 mm.
Flowering from May to July, fruiting from June to
November.
China. Yunnan (云南): Xishuangbanna (西双版
纳), Mengla (勐腊), abundant in forest, alt. 790 m,
2005-06-09, X. F. Deng & H. Ren (邓小芳, 任辉) 410
(holotype, IBSC; isotype, IBSC).
Additional specimens examined:
China. Yunnan (云南): G. D. Tao (陶国达) 7070 (KUN);
Cangyuan (沧源), G. D. Tao & H. W. Li (陶国达, 李锡文)
39895, 39913, 40050 (KUN); Hekou (河口), Hekou Exped. (河
口队) 57, H. Li (李恒) 149 (KUN), W. S. Liu (刘伟心) 188,
768 (KUN); Jiangcheng (江城), Y. Y. Qian (钱义咏) s.n.
(Herbarium No. 110058) (HITBC); Jinping (金平), Lüchun
Exped. (绿春队) 1134 (KUN); Lüchun (绿春), T. L. Ming et al.
(闵天禄等) 124 (KUN), Y. M. Shui & W. H. Chen (税玉民, 陈
文红) 13356, 13369, 13396 (KUN), D. D. Tao (陶德定) 489
(KUN), H. Wang (王洪) 8557, 8558, 8559, 8560 (HITBC,
IBSC); Mengla (勐腊), Anonymous 59-1148 (KUN), X. F.
Deng & L. Gu (邓小芳, 顾垒) 503 (IBSC), X. F. Deng & H.
Ren (邓小芳, 任辉) 404, 456, 457, 459, 461, 462 (IBSC), H.
Koyama et al. (小山博滋等) 313 (KUN), G. D. Tao (陶国达)
13701, 16694 (KUN), C. Y. Wu (吴征镒) 46 (KUN); Mengzi
(蒙自), S. T. Li (李生堂) 173 (KUN); Ruili (瑞丽), 1986 Exped.
(86 年考察队) 1189 (KUN); Shuangjiang (双江), G. S. Sin (辛
景三) 1060 (KUN); Yingjiang (盈江), 1986 Exped. (86 年考察
队) 1085, 1112 (KUN), Q. Lin (林勤) 770799 (KUN), G. D.
Tao (陶国达) 13148, 13529 (KUN); Yuanyang (元阳), Lüchun
Exped. (绿春队) 1205 (KUN).
Journal of Systematics and Evolution Vol. 46 No. 2 2008 224



Fig. 2. Mussaenda lancipetala. A, flowering branch; B, flower; C, calyx and pistil; D, stigma; E, corolla opened showing sta-
mens; F, anther. Drawn by Y. X. Liu from X. F. Deng & H. Ren 410 (holotype, IBSC).

DENG & ZHANG: Mussaenda lancipetala, a new species of Rubiaceae from China

225
Acknowledgements We are indebted to Prof.
Qi-Ming HU for revising the Latin description, Ms.
Yun-Xiao LIU for the illustrations, Ms. Xiao-Ying
HU for technical assistance with SEM observation,
and Mr. Hong WANG, Mr. Shi-Shun ZHOU, Miss
Hui REN and Mr. Lei GU for their assistance during
the field trips. This work was supported by the Sci-
ence Foundation of China, Grant No. 30570314,
Chinese Academy of Sciences Knowledge Innovation
Program, Grant No. KSCX2-YW-Z-027, and the
Natural Science Foundation of Guangdong Province,
Grant No. 04002308.
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Appendix Vouchers cited in this study
Taxon Locality Voucher
Mussaenda lancipetala Mengla, Xishuangbanna, Yunnan, China (中国云南西双版纳勐腊) X. F. Deng & H. Ren (邓小芳, 任辉) 410 (IBSC)
M. roxburghii Sikkim, Gangtok (Orchid Sanctuary) H. Harn et al. 69117 (KUN)
中国玉叶金花属(茜草科)植物一新种
1,2邓小芳 1张奠湘*
1(中国科学院华南植物园 广州 510650)
2(农业部环境保护科研监测所 天津 300191)

摘要 报道了在云南发现的玉叶金花属Mussaenda一新种——狭瓣玉叶金花M. lancipetala X. F. Deng & D. X. Zhang。狭瓣玉
叶金花的性系统为柱头缩入式雌雄异位; 花冠裂片卵状披针形且具有细长的长尖头, 花冠管外被有粉末状的毛被, 可以很容
易与玉叶金花属其他种类相区别。
关键词 玉叶金花属; 狭瓣玉叶金花; 新种; 花粉形态学; 性系统; 分类学