Botanical Studies (2009) 50: 101-106.

*

Corresponding author: E-mail: Libing.Zhang@mobot.org;

Tel: +1-314-577-9454; Fax: +1-314-577-9596.

INTRODUCTION

The current circumscription of Polystichum Roth

(Dryopteridaceae) goes back to Ching¡¦s removal of

Cyrtogonellum Ching (1938) and Cyrtomidictyum Ching

(1940) from Polystichum and allies. Polystichum, o ne

of the ten largest genera of ferns (Little and Barrington,

2003), contains about 300 species (Barrington, 1995;

Kung et al., 2001) or slightly more than 225 species

(Fraser-Jenkins, 1991). This genus is nearly cosmopolitan,

but the species are most numerous in subtropical regions,

with the highest diversity clearly in Asia, especially in

southwestern China and adjacent regions (Kung et al.,

2001). Flora Reipublicae Popularis Sinicae vol. 5(2)

documents 168 species for China (Kung et al., 2001), with

new species constantly being described (e.g. Jiang et al.,

2000; Wang and Wang, 2001, 2003; Zhang and He, 2009).

Polystichum was determined to be paraphyletic

in relation to Cyrtomidictyum Ching, Cyrtogonellum

Ching, and Cyrtomium C. Presl subser. Balansana Ching

& Shing (Little and Barrington, 2003; Li et al., 2004,

2008; Driscoll and Barrington, 2007; Lu et al., 2007).

The species of Polystichum sects. Crucifilix Tagawa,

Haplopolystichum Tagawa, Mastigopteris Tagawa,

Micropolystichum Daigobo, and Sphaenopolystichum

Ching ex W. M. Chu & Z. R. He (which we refer to as

Polystichum sect. Haplopolystichum sensu lato [s.l.]),

together with Cyrtogonellum, Cyrtomidictyum, and

Cyrtomium subser. Balansana, form a strongly supported

monophyletic clade based on chloroplast rbcL, rps4-

trnS, and trnL-F sequences (BCPC clade; Lu et al., 2007;

CCPC clade, Li et al., 2008). Based on morphology, these

relationships seem strange, but the synapomorphy of the

once-pinnate lamina or its modifications unites the species

of Polystichum sect. Haplopolystichum s.l. The detailed

relationships among the species of sect. Haplopolystichum

s.l. and among sect. Haplopolystichum s.l., Cyrtogonellum,

Cyrtomidictyum, and Cyrtomium subser. Balansana have

not yet been resolved and only about one-fifth of the

species were sampled in previous molecular studies (Little

and Barrington, 2003; Perrie et al., 2003; Li et al., 2004,

2008; Driscoll and Barrington, 2007; Lu et al., 2007).

Polystichum sect. Haplopolystichum s.l. contains c. 60

species, of which c. 90% are endemic to the limestone-

derived soil in lowland areas of southwestern China

(Kung et al., 2001). In this paper, we describe a new

species of this group of Polystichum, more exactly, of

sect. Haplopolystichum sensu stricto (s.s.; Daigobo, 1972),

found in 2007 in southern Guizhou Province, China.

Although it has been suggested that Cyrtomidictyum

should be expanded to include the whole monophyletic

BCPC (or CCPC) clade containing Polystichum sect.

Haplopolystichum s.l., Cyrtogonellum, Cyrtomidictyum,

Polystichum peishanii (sect. Haplopolystichum,

Dryopteridaceae): A new fern species from a limestone

area in Guizhou, China

Li-Bing ZHAnG

1,

* and Hai HE

2

1

Chengdu Institute of Biology, Chinese Academy of Sciences, P.O. Box 416, Chengdu, Sichuan 610041, P. R. China and

Missouri Botanical Garden, P.O. Box 299, St. Louis, Missouri 63166-0299, USA

2

Department of Biology, Chongqing Normal University, Shapingba, Chongqing 400047, P. R. China

(Received May 13, 2008; Accepted September 19, 2008)

ABSTRACT.

Polystichum peishanii L.B. Zhang & H.He (sect. Haplopolystichum, Dryopteridaceae), from

Guizhou Province, China, characterized by large pinnae with acute apices and entire margins, a combination

of features not known in other species of Polystichum sect. Haplopolystichum, is described as new.

Polystichum peishanii is similar to P. guangxiense W.M. Chu & H.G. Zhou, but differs in having the lamina

contracted toward the base, the pinnae apically acute, chartaceous and much larger, and larger scales on the

stipe. Polystichum peishanii also resembles P. deltodon (Baker) Diels, but is distinguishable by its oblong-

triangular and much larger pinnae with entire margins. Polystichum peishanii is currently known from only

three localities in southern Guizhou Province, near the border with Guangxi, China.

Keywords: China; Dryopteridaceae; Guizhou; Limestone flora; new species; Polystichum peishanii; sect.

Haplopolystichum s.l.

TAxONOmy

102

Botanical Studies, Vol. 50, 2009

and Cyrtomium subser. Balansana (Little and Barrington,

2003), we assign our new species to Polystichum. Until

the relationships within this clade are well resolved with

good sampling, it is premature to revise the nomenclature

of Polystichum and its allies.

DESCRIPTION

Polystichum peishanii L. B. Zhang & H. He, sp. nov.

¢w TyPE: CHInA. Guizhou Province: Libo Xian,

Weng¡¦ang Township, Dongduo Village, near Guangxi

Autonomous Region border, 25¢X13.12¡¦n, 107¢X59.26¡¦

E, alt. 777 m, broadleaved evergreen forest, stony soil

derived from limestone in a ravine, 16 Sep 2007, L. B.

Zhang, H. He, B. Xu & Y. Wang 457 (HoLoTyPE:

Mo; ISoTyPES: CDBI, CTC, Mo).

°öµ½¦Õ¿¹

Figures 1, 2

Species affinis P. guangxiensi W. M. Ch u et H . G.

Zhou et P. deltodonti (Baker) Diels var. henryi Christ;

differt a P. guangxiensi lamina basin versus contracta

(in P. guangxiensi non contracta), pinnis apice acutis (in

P. guangxiensi rotundatis), majoribus (2.4-3.3 ¡Ñ 1.1-1.3

cm; in P. guangxiensi 1.7-2 ¡Ñ 0.6-0.8 cm), chartaceis (in

P. guangxiensi subcoriaceis), paleis stipitum majoribus

(c. 10 ¡Ñ 1.5-1.8 mm; in P. guangxiensi 5-6 ¡Ñ 1-1.5 mm);

a P. deltodonti pinnis oblongo-triangularis majoribus

(in P. deltodonti 0.8-2 ¡Ñ 0.4-1 cm), margine integris non

spinosis.

Plants perennial, evergreen, 36-75 cm tall. Rhizome

erect; scales lanceolate, dark brown. Fronds cespitose;

petiole 14-32 cm long, 1.5-2 mm in diam. at middle,

adaxially canaliculate, yellowish green; basal petiole

scales broadly lanceolate, c. 10 ¡Ñ 1.5-1.8 mm, chartaceous,

brown, margin obtusely toothed, apex acuminate, matte;

distal petiole scales similar but narrower and shorter

toward apex of stipe and base of rachis, differing in

size, narrowly lanceolate to subulate, chartaceous, dark

brown, margin shortly and sparsely ciliate, apex caudate

or acute, matte. Lamina lanceolate, simply pinnate, 22-43

¡Ñ 4.5-6.5 cm, base slightly contracted, apex caudate,

adaxially lustrous green when fresh; rachis c. 1.5 mm in

diam., without proliferating buds, adaxially canaliculate,

rachis scales subulate, dark brown. Pinnae 18-38 pairs,

two basal pairs 1.7-2.3 cm apart, alternate, attached at c.

80-degree angle to rachis, 2.4-3.3 ¡Ñ 1.1-1.3 cm, shortly

stalked, oblong-triangular, chartaceous, acroscopic base

auriculate, basiscopic base cuneate, margin entire, apex

acute, abaxially scaly, adaxially glabrous; microscales

present on abaxial surface, subulate, to 1 cm long; adaxial

midrib concave, abaxially raised; lateral veins free, once

dichotomous, c. 11 pairs from midrib per pinna, abaxially

raised and obvious, adaxially indistinct. Sori terminal

on veins of upper pinnae, 1-20 per fertile pinna, c. 1

mm distant from pinna margin, yellowish when young,

brown when old; indusia peltate, c. 1 mm in diam.,

membranaceous, yellowish brown, margin repand.

Additional specimens examined. CHINA. Guizhou

Province: Pingtang Xian,Tangbian Township, Dadaihe

Village, Sinkhole Group, 25¢X36.46¡¦ n, 106¢X49.04¡¦E, alt.

1,070 m, under broadleaved forest, in limestone crevices,

24 oct 2008, L. B. Zhang, H. He & C. B. Jiang 778 (CDBI,

CTC, Mo). Guizhou Province: Libo Xian, Dongtang

Township, Banzhai Village, Langgan to Limingguang

Pass, 25¢X12.98¡¦ n, 108¢X01.63¡¦ E, alt. 700 m, under

broadleaved forest, on limestone wall, 30 oct 2008, L. B.

Zhang, H. He & C. B. Jiang 875 (CDBI, CTC, HGAS,

Mo).

Distribution. Polystichum peishanii is known only

from two counties, Libo Xian and Pingtang Xian, in

southern Guizhou, China (Figure 3) at around 700-1,070

m. only c. 50 individuals were found in three localities

(two in Libo Xian and one in Pingtang Xian) cited above

and the two farthest localities are separated by c. 120 km

(air line). The new species is likely to be found in other

places in Libo Xian and Pingtang Xian and in the adjacent

Guangxi Autonomous Region in China.

Ecology. Broadleaved evergreen forests dominated

b y Cyclobalanopsis glauca mixed with Celtis sinensis

and Zelkova serrata at 700-1,070 m, on basic black soil

derived from limestone in ravines. Associated plants

include Asparagus cochinchinensis, Carex sp., Centella

asiatica, Cyrtomium grossum and various seed plants.

Etymology. We name Polystichum peishanii in honor

of Professor Peishan Wang of the Guizhou Institute of

Biology, Guizhou Academy of Sciences, Guiyang, for his

long and dedicated study of the fern diversity of Guizhou,

China. He is the senior author of the Pteridophyte Flora

of Guizhou, which documents the 770 species of ferns and

lycophytes in the province (Wang and Wang, 2001).

Morphological notes. The discovery of P. peishanii

in southern Guizhou Province, on the bordering with

Guangxi Autonomous Region, is reminiscent of the

discovery of P. guangxiense, described from napo, western

Guangxi (Zhou et al., 1996), about 310 km southwest of

Libo, where P. peishanii was discovered. Indeed these

two species share more or less oblong pinnae with entire

margins and sori located close to the pinna margins. The

two species differ in the following ways: P. peishanii has

the lamina contracted toward the base, chartaceous pinnae,

acute apices, and larger scales on base of the stipe. The

lamina of P. guangxiense is not contracted toward the base,

the pinnae are smaller (1.7-2 ¡Ñ 0.6-0.8 cm), and nearly

coriaceous, with the apex obtuse; the scales at the base of

the stipe are also smaller (c. 5-6 ¡Ñ 1-1.5 mm).

Polystichum peishanii also resembles P. deltodon var.

deltodon in that both have the apex of the pinnae acute, but

the margins of the pinnae of P. peishanii are nearly entire,

while the pinna margins of P. deltodon var. deltodon are

toothed. notably, the margins of the pinnae of P. deltodon

var. henryi are nearly entire. Both P. deltodon var. deltodon

and var. henryi have triangular, much smaller pinnae

(1.7-2 ¡Ñ 0.6-0.8 cm) with the apex mucronate. neither P.

deltodon var. deltodon nor var. henryi occur in southern

Guizhou (Kung et al., 2001; Wang and Wang, 2001).

ZHANG & HE ¡X

Polystichum peishanii

, new species from Guizhou, China

103

Figure 1. Polystichum peishanii. A, Frond; B, Pinna; C, Scale from base of stipe; D, Rachis scale; E, Microscales; F, Indusium (From

the holotype, L. B. Zhang, H. He, B. Xu & Y. Wang 457, Mo).

104

Botanical Studies, Vol. 50, 2009

Figu re 2. Polystichum peishanii. A, Dongduo Village among well preserved evergreen vegetation dominated by Cyclobalanopsis

glauca, under which the new species was found; B, Habitat, showing slightly contacted lamina base; C, Portion of stipe, showing

brown lanceolate scales; D, Portion of lamina, showing current year¡¦s yellowish sori; E, Portion of lamina, showing oblong-triangular

pinnae with previous year¡¦s brown sori; F, Portion of lamina, showing rachis scales; G, Portion of lamina, showing caudate apex.

ZHANG & HE ¡X

Polystichum peishanii

, new species from Guizhou, China

105

I n Polystichum sect. Haplopolystichum s.s., there

are seven species in China with apically acute pinnae

that are attached at nearly right angles to the rachis and

mostly not reflexed towards the lamina base. The length

to width ratio of the pinnae is . 2. These seven species

are P. deltodon (including var. deltodon, var. henryi, and

var. cultripinnum W. M. Chu & Z. R. He), P. muscicola

Ching ex W. M. Chu & Z. R. He, P. nayongense P. S.

Wang & X. y. Wang, P. obliquum (D. Don) T. Moore, P.

paradeltodon L. L. Xiang, P. rupicola Ching ex W. M.

Chu, and P. peishanii. Polystichum deltodon occurs in

eastern, central and southwestern China, Taiwan, Japan,

Myanmar, and the Philippines; P. muscicola is in western

Sichuan and western Hubei; P. nayongense is in southern

and northern Sichuan, western Guizhou, and southeastern

yunnan; P. rupicola is in northwestern yunnan; P.

obliquum is in the Sino-Himalayan region from Jammu

and Kashmir eastward and in Taiwan, and P. paradeltodon

is in northwestern Guangxi, western Guizhou, and

yunnan (Kung et al., 2001). These seven species can be

distinguished by the following key:

Figu re 3. Geographical distribution of Polystichum peishanii

(

¡´

) in southern Guizhou Province, China.

Key to Polystichum obliquum and its allies

1. Margin of pinnae aristate.

2.

Lamina less than 20 ¡Ñ 1.8 cm; pinnae ovate or ovate-oblong, less than 1 ¡Ñ 0.6 cm, nearly bilaterally symmetrical

........................................... ........................................................................................................................... P. muscicola

2.

Lamina more than 25 ¡Ñ 2 cm; pinnae oblong or shortly falcate, middle pinnae more than 1.5 ¡Ñ 0.7 cm, obviously

bilaterally asymmetrical.

3.

Pinnae oblong, apex mostly round or acute¡K..................¡K...............¡K¡K¡K¡K..... ................................. P. rupicola

3.

Pinnae falcate, falcate-oblong, oblong or rarely nearly triangular, apex often acute.

4.

Acroscopic margin of pinnae below middle of lamina repand or crenulate

............. P. deltodon var. cultripinnum

4.

Acroscopic margin of pinnae serrate or biserrate.

5.

Margin of pinnae regularly serrate and obviously aristate-spinose ............................................ P. nayongense

5.

Margin of pinnae irregularly serrate or biserrate and shortly spinose ......................... P. deltodon var. deltodon

1.

Margin of pinnae not aristate; or if so, pinnae rhombic-ovate.

6.

Margin of pinnae entire; pinnae 2.4-3.3 ¡Ñ 1.1-1.3 cm

.................................................................................... P. peishanii

6.

Margin of pinnae repand or slightly toothed; pinnae less than 2 ¡Ñ 1 cm.

7.

Pinnae ovate, rhombic-ovate or rarely oblong, 7-15 pairs; sori between midrib and margin of pinnae ... P. obliquum

7.

Pinnae oblong or falcate-oblong, 16-40 pairs; sori between midrib and margin or close to margin of pinnae.

8.

Sori close to margin of pinnae; pinnae up to 40 pairs ..........................................................P. deltodon var. henryi

8.

Sori between midrib and margin or slightly closer to margin of pinnae; pinnae fewer than 20 pairs ..................

........................................................................................................................................................P. paradeltodon

Acknowledgements. This project was partly supported

by funding from the open Laboratory of Biodiversity

Conservation and Ecology of the Chengdu Institute of

Biology, Chinese Academy of Sciences, to LBZ, the Flora

of China project, and a national Geographic Society grant

(#825407) to LBZ. Peishan Wang, yu Wang, Bo Xu, and

Chunbao Jiang helped with the field work. Yingbao Sun

prepared the basic line drawing. Helpful comments were

received from David Barrington, David Boufford, C. R.

Fraser-Jenkins, and an anonymous reviewer. The curators

of the herbaria at CDBI, CTC, and Mo are acknowledged

for allowing access to specimens.

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