Microsoft Word - 05. Persicaria lankeshanensis_Revised-9.9.14_EE.doc


Bangladesh J. Plant Taxon. 21(2): 147-152, 2014 (December) 
© 2014 Bangladesh Association of Plant Taxonomists 
 

PERSICARIA LANKESHANENSIS (POLYGONACEAE: PERSICARIEAE), A 
NEW SPECIES FROM GUANGDONG, CHINA 

 

TONG-JUN LIANG AND BO LI1,2 
 

Lushan Botanical Garden, Jiangxi Province and the Chinese Academy of Sciences,  
Jiujiang, 332900, China 

 

Keywords: New species; Persicaria lankeshanensis; China; Micromorphology.  
 

Abstract 
    Persicaria lankeshanensis, a new species of Polygonaceae from the Lankeshan Nature 
Reserve, Guangdong province of China, is described and illustrated. Persicaria lankeshanensis 
is similar to P. taquetii but differs from the latter by having stems, leaves, and ocreae densely 
pubescent, pedicels shorter than bracts, smaller flowers and achenes, and achenes opaque and 
minutely granular-striate. A comparison of achenes, pollen and abaxial leaf epidermis between 
the two species is provided. 

 

Introduction  
 Persicaria [Tourn.] ex Mill. contains c. 150 species of prostrate or twining annual or perennial 
herbs, and are distributed mainly in northern temperate and tropical regions (Brandbyge, 1993). It 
is characterized by many-flowered, spike-like or capitate inflorescence; usually entire, ciliate, or 
pectinate ocreae; 4–5-parted perianths; tepals with trifid venation; the presence of nectaries; 4–8 
stamens (Haraldson, 1978; Ronse Decraene and Akeroyd, 1988); and mostly rectangular to 
elongated tepal epidermis cells with straight or slightly undulating anticlinal walls (Hong et al., 
1998). Within Persicaria, Haraldson (1978) recognized four sections, viz. Cephalophilon (c. 16 
species), Echinocaulon (c. 21 species), Persicaria (c. 60 species), and Tovara (c. 3 species). Qaiser 
(2001) accepted this treatment, while Freeman (2005) included Rubrineva (c. 2 species) and Hou 
(2006) excluded Tovara. 
 During a field trip in September 2009 in the Lankeshan Provincial Nature Reserve in 
Guangdong Province of China, a slender Persicaria with completely interrupted spike-like 
inflorescence, densely pubescent stems, leaves, and ocreae, and tiny flowers and fruits was 
collected. The plants superficially resemble P. taquetii (H. Lév.) Koidz., but can be distinguished 
by a suite of morphological and micromorphological characters. After critical study we recognized 
it as a new species, Persicaria lankeshanensis sp. nov. 
 

Materials and Methods 
    Morphological comparisons of the new species and its related taxa were carried out based on 
both herbarium specimens and live plants. Characters were measured using a micrometer and a 
stereomicroscope. Field studies were carried out from 2009 to 2011.  
 For scanning electron microscopy (SEM) observations, samples of achenes and pollen were 
removed from mature fruits and unopened flowers, respectively, from the herbarium specimens. 
After cleaned in 95% ethanol, mounted onto cupreous stubs, and coated by JFC-1100E sputter 
coater (JEOL Led., Janpan), samples were examined under JSM-6360LV SEM (JEOL Led., Japan) 
at a voltage of 15 KV. Terminology for achenes and pollen follows Hou (2006) and Zhang and 
Zhou (1998), respectively. 
 
1Laboratory of Subtropical Biodiversity, Jiangxi Agricultural University, Nanchang, 330045, China 
2Corresponding author. Email: hanbolijx@163.com 



148 LIANG AND LI 

 For light microscopy (LM) investigation of leaf epidermis, samples were taken from mature 
leaves of live plants, fixed in FAA solution (18 formalin:1 acetic acid:1 ethanol), dissected under a 
Zeiss stereoscope, and stained in a solution of 1% safranin before being mounted in glycerine jelly. 
Measurements and counts were conducted randomly from 5 areas in the prepared slide per species 
under LM. Stomatal density was calculated using the formula S/M × 100%, where S is the number 
of stomata in a given area (M). Terminology follows Zhu et al. (2007). 
 
Persicaria lankeshanensis T. J. Liang & B. Li, sp. nov. (Figs 1 & 2). 
 Diagnosis: Species P. taquetii (H. Lév.) Kodiz. affinis, sed caules, folia, ochreae dense 
pubescens, perianthia 0.7-1.0 mm, achenia striato–granulatis, 0.7–1.0 × 0.5–0.7 mm differt.  
 Type: CHINA. Guangdong: Zhaoqinq city, Lankeshan Provincial Nature Reserve, growing in 
wet grassy slopes along river side, altitude 200 m, 23°08′38″N, 112°35′20″E, 24 Sep 2009, Bo Li 
0075 (Holotype: IBSC; Isotype: JXAU). 
 Annual herbs. Stems erect, prostrate, or ascending at base, 15-35 cm tall, slender, densely 
pubescent, much-branched from base, rooting at proximal nodes. Leaves: ocreae tubular, 4-6 mm 
long, membranous, densely pubescent, apex truncate, cilia 3-5 mm long; petioles nearly absent; leaf  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

 
 
 
Fig. 1. Persicaria lankeshanensis T. J. Liang & B. Li, sp. nov. A. Habit; B. Inflorescence; C. Bract; D. Ocrea 

and leaf (all from the type, Bo Li 0075, IBSC).  



A NEW SPECIES OF PERSICARIA FROM CHINA 149 

blades narrowly lanceolate, 15-30 × 4-8 mm, both surfaces densely pubescent, base narrowly  
cuneate, or slightly rounded, margin entire, ciliate, apex acute. Inflorescence terminal or rarely 
axillary, spike-like, erect, 1.5-2.5 cm long, slender, interrupted. Bracts green, funnelform, 1.5-2.0 
mm long, densely pubescent, margin submembranous, ciliate, each 2-3-flowered. Pedicels 0.8-1.3 
mm long, much shorter than subtending bracts. Perianth white, 5-parted, lobes (or tepals) elliptic, 
0.7-1.0 mm long. Stamens 7, included. Styles 3, included, connate to below middle; stigmas 
capitate. Achenes included or slightly exserted from persistent perianth, brown-black, minutely 
granular-striate, opaque, ovoid, trigonous, 0.7-1.0 x 0.5-0.7 mm.  
 Phenology: Flowering: August - October; fruiting; September - November. 
 Etymology: The specific epithet is derived from the type locality. 
 Distribution and habitat: Persicaria lankeshanensis is known only from two nearby localities 
in Lankeshan Provincial Nature Reserve, Guangdong province of China, from where it was first 
collected in 2009. It grows in wet, grassy slopes along river sides at an altitude of 100-200 m. 
 Notes: Persicaria lankeshanensis bears a superficial resemblance to P. taquetii in having very 
slender and completely interrupted inflorescence, tiny flowers and fruits, 7 stamens, small and 
narrowly lanceolate leaves, and slender stems. However, P. lankeshanensis differs from P. taquetii 
in plant indumentum, pedicel length, tepal length, and achene size and surface texture (Table 1; Fig. 
3A vs. E).  
 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

 
 
 
Fig. 2 Persicaria lankeshanensis T.J. Liang & B. Li, sp. nov. A. Habit; B. A part of stem with ocrea showing 

pubescence; C. Pubescence of adaxial surface of leaf blade; D. Inflorescence.    



150 LIANG AND LI 

    In Persicaria, achenes (Yang et al., 1991; Ronse Decraene et al., 2000; Qu et al., 2006), 
abaxial leaf epidermis (Meng et al., 1997; Zhu et al., 2007; Yasmin et al., 2010a), and pollen 
(Hedberg, 1946; Wang and Feng, 1994; Zhang and Zhou, 1998; Yasmin et al., 2010b) have been 
proved to be useful characters for the species delimitation. In this study, we found that P. 
lankeshanensis and P. taquetii also can be distinguished from each other by the epicarp sculpturing 
of the achenes, the shape of the epidermal cells on the abaxial leaf surface, the type of stomata, and 
pollen size and ornamentation (Table 1, Fig. 3).  
 

Table 1. Comparison of Persicaria lankeshanensis sp.nov. with P. taquetii.  
 

Characters P. lankeshanensis sp. nov. P. taquetii 
Plant indumentum Stems, leaves, and ocreae densely 

pubescent 
Leaves and ocreae sparsely pubescent 
or rarely glabrous, stems glabrous 

Pedicel 0.8-1.3 mm long, much shorter than bracts 1.8-2.7 mm long, obviously longer 
than bracts 

Tepal 0.7-1.1 mm long 1.4-1.6 mm long 
Achene     

Size (L × W) 0.8 (0.7-1.0) × 0.6 (0.5-0.7) mm 1.5 (1.3-1.6) × 0.8 (0.7-1.0) mm 
Surface Opaque, minutely granular striate Shiny, smooth 
Epicarp sculpturing With irregular ridges formed by oblate 

tubercles following a longitudinal pattern 
With irregular hollows 

Leaf abaxial epidermis   
Epidermal cell shape and 
anticlinal wall 

Polygonal, straight or curved Irregular, sinuolate 

Stomatal type Anisocytic Paracytic, rarely anisocytic 
Stomatal density 88.1 / mm2 168.5 / mm2 

Pollen   
Size 31.1-36.7 µm 37.5-56.8 µm 
Width between two adjacent 
pores 

8.2-12.3 µm 11.2-17.4 µm 

Lumen number across the 
diameter 

9-12 6-9 

Lumen size 3.8-4.7 µm 6.4-10.1 µm 
Granules in a lumen Obscure, undeveloped 25-40, well developed 
Number of coarse granules of 
murus in cross-section under 
LM 

18-22 14-17 

Width between two adjacent 
granules under LM 

3.9-5.3 µm 8.2-11.3 µm 

 

 Additional specimens examined: CHINA. Guangdong Province: Zhaoqinq City, at the 
boundary of the Lankeshan Provincial Nature Reserve, 23°08′15″N, 112°34′58″E, alt. 15 m, 8 Oct 
2010, Bo Li and Zhu-Qiu Song 201002 (IBSC).  
    Conservation status: Persicaria lankeshanensis is only recorded from the Lankeshan 
Provincial Nature Reserve, Guangdong, China. Given the species was observed only in two nearby 
localities in a about 5 km2 area at the nature reserve, we propose to categorize it as Vulnerable (VU) 
on the IUCN Red List, according to the criteria D2 (IUCN, 2001).  
 

 

 

 



A NEW SPECIES OF PERSICARIA FROM CHINA 151 

 

 
  
     
 
  
 

 

 

 

 

 

 

 
 
 
 

 
 
 
 
Fig. 3. Micromorphology of Persicaria lankeshanensis (A–D, I, K) and P. taquetii (E–H, J, L). A,B,E,F. 

Achene morphology under scanning electron microscopy (SEM); A,E. Lateral view; B,F. Epicarp 
sculpturing, C,D,G,H. Pollen morphology under SEM; C,G. Whole view; D,H. Lumen and granules 
inside; I,J. Pollen morphology under light microscopy (LM); K,L. Leaf abaxial epidermis under LM. 
Scale bars: A,E = 100 µm; B,F,K,L = 50 µm; C,G,I,J = 10 µm; D,H = 5 µm.  

 
Acknowledgements  
 The authors are grateful to Prof. An-Jen Li of the Institute of Botany, Chinese Academy of 
Science, for identifying specimens, to Ms. Yun-Xiao Liu and Ms. Xiao-Ying Hu, South China 
Botanical Garden, Chinese Academy of Sciences, for the illustrations and SEM observations, 
respectively, and to Mr. Zhu-Qiu Song for field assistance. 
 
References 
Brandbyge, J. 1993. Polygonaceae. In: Kubitzki, K. and Bittich, V. (Eds), The Families and Genera of Vascular 

Plants. Vol. 2. Springer Verlag, Berlin, pp. 531-544. 
Freeman, C.C. 2005. Polygonaceae. In: Flora of North America Editorial Committee, Flora of North America. 

Vol. 5. Oxford University Press, New York, pp. 574-594. 
Haraldson, K. 1978. Anatomy and taxonomy in Polygonaceae subfam. Polygonoideae Meisn. emend Jaretzky. 

Symb. Bot. Upsal. 22: 1-95. 
Hedberg, O. 1946. Pollen morphology in the genus Polygonum L. s.l. and its taxonomical significance. 

Sven. Bot. Tidskr. 40: 371-414. 



152 LIANG AND LI 

Hong, S.P., Ronse Decraene, L.P. and Smets, E. 1998. Systematic significance of tepal surface morphology in 
tribes Persicarieae and Polygoneae (Polygonaceae). Bot. J. Linn. Soc. 127: 91-116. 

Hou, Y.T. 2006. Systematic studies on the tribe Polygoneae of China. Shandong Normal University, Jinan, 306 
pp. 

IUCN 2001. IUCN red list categories and criteria, v. 3.1. IUCN Species Survival Commission, Switzerland. 
Meng, R.X., Zhou, Z.Z. and Wang, S.L. 1997. A study on foliar epidermis of genus Polygonum in Anhui. 

Anhui Univ. Nat. Sci. Edit. 21: 81-93. 
Qaiser, M. 2001. Polygonaceae. In: Nasir, E. and Ali, S.I. (Eds), Flora of Pakistan. Vol. 205. Department of 

Botany, Karachi University & Missouri Botanical Garden Press, St. Louis, pp. 1-190. 
Qu, C.Y., Hou, Y.T., Li, A.L., Lu, F.J. and Li, F.Z. 2006. Fruit shape and pericarp micromorphological 

characteristics of Polygonum section Persicaria from China. Bull. Bot. Res. 26: 275-285. 
Ronse Decraene, L.P. and Akeroyd, J.R. 1988. Generic limits in Polygonum and related genera (Polygonaceae) 

on the basis of floral characters. Bot. J. Linn. Soc. 98: 321-371. 
Ronse Decraene, L.P., Hong, S.P., and Smets, E. 2000. Systematic significance of fruit morphology and 

anatomy in tribes Persicarieae and Polygoneae (Polygonaceae). Bot. J. Linn. Soc. 134: 301-337. 
Wang, J.X. and Feng, Z.J. 1994. A study of the pollen morphology of the genus Polygonum L. in China. Acta 

Phyt.. Sin. 32: 219-231. 
Yang, J., Li, Y.H. and Wang, J.W. 1991. A primary study on the microstructural features of achene surfaces and 

its taxonomic importance to Polygonum. Acta Bot. Boreali-Occidentalia Sin. 11: 1-7. 
Yasmin, G., Khan, M.A., Shaheen, N. and Hayat, M.Q. 2010a. Taxonomic significance of leaf epidermal 

anatomy of selected Persicaria Mill. species of family Polygonaceae from Pakistan. Afr. J. Biotechnol. 9: 
3759-3768. 

Yasmin, G., Khan, M.A. and Shaheen, N. 2010b. Pollen morphology of selected Polygonum L. species 
(Polygonaceae) from Pakistan and its taxonomic significance. Pak. J. Bot. 42: 3693-3703. 

Zhang, X.P. and Zhou, Z.Z. 1998. A study on pollen morphology and its phylogeny of Polygonaceae in China. 
University of Science and Technology of China Press, Hefei, 235 pp. 

Zhu, L.T., Lu, F.J. and Hou, Y.T. 2007. Micro-morphology of leaf epidermis and its taxonomical significance 
of Polygonum section Cephalophilon in China. J. Wuhan Bot. Res. 25: 136-142.  

 
 

(Manuscript received on 17 April 2014; revised on 9 September 2014)