Research Article
Print
Research Article
A new species of Hypodematium (Hypodematiaceae) from China
expand article infoXiaojuan Li‡, Jianxiu Li§|, Fanyun Meng‡
‡ Beijing Normal University, Beijing, China
§ Shandong University of Traditional Chinese Medicine, Jinan, China
| Shandong Hongjitang Museum, Jinan, China

Corresponding author: Xiaojuan Li ( lixiaojuan124@163.com )

Academic editor: Thais Almeida
© 2018 Xiaojuan Li, Jianxiu Li, Fanyun Meng.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation: Li X, Li J, Meng F (2018) A new species of Hypodematium (Hypodematiaceae) from China. PhytoKeys 92: 37-44. https://doi.org/10.3897/phytokeys.92.21815
Open Access

Abstract

Hypodematium confertivillosum J.X.Li, F.Q.Zhou & X.J.Li, sp. nov., a new species of Hypodematium from Shandong, China, is described and illustrated. It is similar to H. crenatum (Forssk.) Kuhn & Decken and H. glanduloso-pilosum (Tagawa) Ohwi, but differs greatly from them by its abaxial fronds sparsely covered with rod-shaped glandular hairs, its adaxial fronds without rod-shaped glandular hairs and spore reniform, with verrucate processes, surface with distinct finely lamellar rugae ornamentation. The description, photographs and a key to H. confertivillosum as well as their notes are provided.

Keywords

Hypodematium confertivillosum , Hypodematium crenatum , Hypodematium glanduloso-pilosum , spore ornamentation, SEM

Introduction

Described in 1833, Hypodematium Kunze is the only genus of Hypodematiaceae Ching (Ching 1975). Iwatsuki (1964) reviewed the genus and recognised four species including one subspecies. Recently, more than 16 species of Hypodematium, mainly distributed in subtropical and temperate areas of Asia and Africa, have been established (Shing et al. 1999). China, with 12 species of Hypodematium, is regarded as the centre of distribution for this genus (Zhang and Iwatsuki 2013). The genus is characterised by a distinctive swollen scaly stipe base and grows only on limestone habitat (Zhang and Iwatsuki 2013). Previous research on systematics and palynology of Hypodematium (Ching 1935, 1940, 1963, 1975, 1978a, b, Li et al. 1988, Shing et al. 1999, Zhou et al. 1999, Wang et al. 2010, Zhang and Iwatsuki 2013) provided an important background that allowed the recognition of the species new to science.

Materials and methods

The voucher specimens of the new species were collected from Tashan mountain, China and deposited in PE (herbaria acronyms according to Thiers 2016).

Scanning electron microscopy (SEM) was used to document the micromorphology of spore and fronds. Samples were dehydrated and were then placed on aluminium stubs using double-sided adhesive tape and sputter coated with gold in a Hitachi E-1010 Ion Sputter Coater, following Wen and Nowicke (1999). The materials were subsequently observed and photographed under a SUPRATM55 scanning electron microscope.

Taxonomy

Hypodematium confertivillosum J.X.Li, F.Q.Zhou & X.J.Li, sp. nov.

urn:lsid:ipni.org:names:77174973-1

Diagnosis

Hypodematium confertivillosum J. X. Li, F. Q. Zhou & X. J. Li is similar to H. crenatum (Forssk.) Kuhn & Decken and H. glanduloso-pilosum (Tagawa) Ohwi, from which it differs greatly by its abaxial fronds sparsely covered with rod-shaped glandular hairs, its adaxial fronds without rod-shaped glandular hairs and spore reniform, with verrucate processes, surface with distinct finely lamellar rugae ornamentation.

Type

China. Shandong Province: Linyi City, Fei County, Tashan Mountain, limestone rocks, 35°33'59.76"N, 117°51'29.51"E, 500–700 m a.s.l., 15 September 1982, J. X. Li 02025 (Holotype: PE, Isotype: SDCM). Figure 1.

Description

Plants 21–32 cm tall. Rhizomes creeping; densely scaly together with stipe base, scales reddish-brown, lustrous, linear-lanceolate, 10–12 × 1–2 mm, membranaceous, margin subentire, apex acuminate. Fronds approximate; stipe stramineous, 7–17 cm × 1–1.2 mm, nearly glabrous upward; laminae pentagonal, 12–17 × 12–14 cm, 3-pinnate-pinnatifid, base round-cordate, apex acuminate and pinnatifid; pinnae 10–12 pairs, slightly oblique, lower 2 pairs sub-opposite, 3–4 cm apart, upper pairs alternate; basal pinnae largest, deltoid-oblong, 10–11 × 8–8.5 cm, 2-pinnate-pinnatifid, base cordate, pinnae tapered; pinnules 6–8 pairs, anadromous, alternate, slightly oblique, acroscopic ones smaller, proximal basiscopic pair largest, ovate-triangular, 5 × 2–3 cm, shortly stalked, base cuneate, pinnae tapered, pinnate-pinnatifid; ultimate pinnules oblong, 8–10 × 4–6 mm, apex obtuse, pinnatifid; lobe oblong, apex obtuse, margins obtuse-serrate; second and upper pairs of pinnae gradually shorter, lanceolate or oblong-lanceolate, 2-pinnate-pinnatifid, base rounded-cuneate or shallowly cordate, with a short stalk, apex shortly acute. Veins obvious on both surfaces, pinnate, simple, ending at margin. Laminas chartaceous, fronds densely covered with long grey hairs adaxially, fronds abaxial surface, rachis and costae densely covered with long grey hairs and sparsely mixed with rod-shaped glandular hairs. Sori round, dorsal, 1–4 per segment; indusia reniform, pale grey, membranaceous, densely covered with grey hairs. Spores reniform, with verrucate processes, surface with distinct finely lamellar rugae ornamentation.

Figure 1. 

Hypodematium confertivillosum J.X.Li, F.Q.Zhou & X.J.Li, sp. nov. A Habit B Sori on the abaxial surface of pinnules C Indusium with long hairs D Rhizome and stipe base scales E Long hairs from the abaxial surface of fronds F Rod-shaped glandular hairs from the abaxial surface of fronds G Hairs from the adaxial surface of fronds (Drawn by Y. B. Sun & J. X. Li).

Distribution

This species is known only from the area around the type locality in Tashan, Shandong.

Ecology

Usually growing in limestone crevices of xeric areas.

Discussion

The perispore is an important trait for identifying species under the scanning electron microscopy (Liu and Li 1999) and it contributes to the discovery of some new species, for example Dryopteris guanchica (Jermy 1980). There are significant differences between the perispore of H. confertivillosum that has verrucate processes, surface with distinct finely lamellar rugae ornamentation, H. crenatum having curved long ridges, surface with fine striae ornamentation and H. glanduloso-pilosum having tuberculate-massive ornamentation, providing an important micromorphological basis for establishment of the new species H. confertivillosum. A comparison of H. confertivillosum, H. crenatum, and H. glanduloso-pilosum is given in Table 1 and Figure 2.

Figure 2. 

Spore morphologies of three Hypodematium species (SEM). A Spore in equatorial view of H. confertivillosum (1500×) B Detail of spore in equatorial view of H. confertivillosum (5000×) C Spore in polar view of H. confertivillosum (1500×) D Detail of spore in polar view of H. confertivillosum (5000×) E Spore in equatorial view of H. crenatum (1500×) F Detail of spore in equatorial view of H. crenatum (5000×) G Spore in equatorial view of H. glanduloso-pilosum (1500×) H Detail of spore in equatorial view of H. glanduloso-pilosum (5000×).

Table 1.
Download as
CSV
XLSX

Comparison of spore morphological features amongst three species of Hypodematium.

Species name Size (μm) Ornamentation of perispore SEM Locality and voucher Figure 2
H. confertivillosum 40.8×52.6 Verrucate processes, surface with finely lamellar rugae Shandong J.X. Li 02025 PE A–D
H. crenatum 46.1×50.3 Curved long ridges, surface with fine striae Guangxi R.H. Zhou 0013-1 PE E–F
H. glanduloso-pilosum 48.2×53.6 Tuberculate-massive Shandong J.X. Li 96-035 SDCM G–H

It is commonly believed that Hypodematium, a very special group, has different types of glandular hairs and non-glandular hairs, which is an important basis for the identification and classification of species of Hypodematium (Zhang and Iwatsuki 2013). Hypodematium confertivillosum fronds are sparsely covered with rod-shaped glandular hairs abaxially, but its adaxial fronds without rod-shaped glandular hairs; H. crenatum fronds are sparsely covered with acicular hairs adaxially, densely covered with long hairs abaxially and without rod-shaped glandular hairs on both surfaces. Hypodematium glanduloso-pilosum fronds are mixed, densely covered with acicular and rod-shaped glandular hairs adaxially and long hairs and rod-shaped glandular hairs abaxially. Therefore, the types of hair and the degree of density of different types of hair support the establishment of the new species of H. confertivillosum. A comparison of H. confertivillosum, H. crenatum, and H. glanduloso-pilosum is given in Table 2 and the taxonomic key below (adapted from Zhang and Iwatsuki 2013), and Figure 3.

Figure 3. 

The fronds and rachis of H. confertivillosum, H. crenatum and H. glanduloso-pilosum (SEM). A H. confertivillosum fronds densely covered with long hairs adaxially (30×) B H. confertivillosum fronds and indusia densely covered with long hairs and sparsely rod-shaped glandular hairs abaxially (30×) C H. confertivillosum fronds and costae densely covered with long hairs and sparsely rod-shaped glandular hairs abaxially (30×) D H. confertivillosum costae densely covered with long hairs and sparsely rod-shaped glandular hairs abaxially (160×) E H. crenatum fronds sparsely covered with acicular hairs adaxially (60×) F Close-up view of H. crenatum fronds covered with acicular hairs adaxially (140×) G H. crenatum fronds and indusia densely covered with long hairs abaxially (30×) H Close-up view of H. crenatum indusia covered with long hairs abaxially (60×) I H. glanduloso-pilosum fronds densely covered with acicular hairs and rod-shaped glandular hairs adaxially (30×) J Close-up view of H. glanduloso-pilosum fronds covered with acicular hairs and rod-shaped glandular hairs adaxially (140×) K H. glanduloso-pilosum fronds and indusia densely covered with long hairs and rod-shaped glandular hairs abaxially (30×) L Close-up view of H. glanduloso-pilosum fronds covered with long hairs and rod-shaped glandular hairs abaxially (140×)

Table 2.
Download as
CSV
XLSX

Comparison of fronds and indusia in three species of Hypodematium.

Species name Adaxial fronds Abaxial fronds Rachis and costae Indusia Holotype, voucher and gatherer Figure 3
Non-glandular hairs Glandular hairs Non-glandular hairs Glandular hairs Non-glandular hairs Glandular hairs Non-glandular hairs Glandular hairs
H. confertivillosum Densely covered with long grey hairs Absent Densely covered with long grey hairs Sparsely rod-shaped glandular hairs Densely covered with long grey hairs Sparsely rod-shaped glandular hairs Densely covered with long grey hairs Sparsely rod-shaped glandular hairs Holotype
J. X. Li 02025		 A–D
H. crenatum Sparsely acicular hairs Absent Densely covered with long grey hairs Absent Densely covered with long grey hairs Absent Densely covered with long grey hairs Absent Voucher
R. H. Zhou 0013-1		 E–H
H. glanduloso-pilosum Densely covered with acicular hairs More rod-shaped glandular hairs Densely covered with long grey hairs Densely covered with rod-shaped glandular hairs Densely covered with long hairs Densely covered with rod-shaped glandular hairs Densely covered with grey hairs Densely covered with rod-shaped glandular hairs Voucher
J. X. Li
96-035		 I–L

Taxonomic key to the species of Hypodematium

1 Fronds not covered with rod-shaped glandular hairs adaxially 2
– Fronds covered with rod-shaped glandular hairs and long grey hairs on both surfaces; perispore with tuberculate-massive ornamentation H. glanduloso-pilosum
2 Fronds sparsely covered with rod-shaped glandular hairs abaxially; perispore with verrucate processes, surface with finely lamellar rugae ornamentation H. confertivillosum
– Fronds not covered with rod-shaped glandular hairs abaxially; perispore with curved long ridges, surface with fine striae ornamentation H. crenatum

Acknowledgments

This work was supported by the Standardisation Construction of Traditional Chinese Medicine on Rehmannia glutinosa (ZYBZH-Y-HEN-18) and the Characteristics of the Commonly Used Chinese Drugs and its Region, Standards and Digital (2015FY111500). We thank Prof. Xianchun Zhang & Prof. Xiangyun Zhu from Chinese Academy of Sciences and Prof. Gangmin Zhang from Beijing Forestry University for the revision of the manuscript.

References

  • Ching RC (1935) On the genus Hypodematium Kunze. Sunyatsenia 3(1): 3–15. [pl. 2]
  • Ching RC (1940) On natural classification of the family Polypodiaceae. Sunyatsenia 5(4): 201–268.
  • Ching RC (1963) A reclassification of the family the Lypteridaceae from the mainland of Asia. Acta Phytotaxonomica Sinica 8(4): 289–335.
  • Ching RC (1975) Two new fern families. Acta Phytotaxonomica Sinica 13(1): 96–98.
  • Ching RC (1978a) The Chinese fern families and genera: systematic arrangement and historical origin. Acta Phytotaxonomica Sinica 16(3): 1–19.
  • Ching RC (1978b) The Chinese fern families and genera: systematic arrangement and historical origin (Cont.). Acta Phytotaxonomica Sinica 16(4): 16–37.
  • Iwatsuki K (1964) On Hypodematium Kunze. Acta Phytotaxonomica et Geobotanica.21: 43–54.
  • Jermy AC (1980) Biosystematic studies of Dryopteris. Acta Phytotaxonomica Sinica 18(1): 37–44.
  • Li JX, Zhou FQ, Zhang YL (1988) Studies on the spore morphology of Hypodematium in China. Proceedings of the International Symposium on Systematic Pteridology: 269–272.
  • Liu JX, Li YX (1999) Study on the spore morphology of Cystopteris Bernh from Beijing. In: Shing K-H (Ed.) Ching Memorial Volume.China Forestry Publishing House, 328–330.
  • Shing KS, Chiu PS, Yao GH (1999) Hypodematiaceae. In: Shing KS (Ed.) Flora Reipublicae Popularis Sinicae, Vol.4(1). Science Press, 151–191.
  • Thiers B (2016) Index Herbariorum: A global directory of public herbaria and associated staff. New York Botanical Garden’s Virtual Herbarium. http://sweetgum.nybg.org/ih/
  • Wen J, Nowicke JW (1999) Pollen ultrastructure of Panax (the ginseng genus, Araliaceae), an eastern Asian and eastern North American disjunct genus. American Journal of Botany 86: 1624–1636. https://doi.org/10.2307/2656799
  • Wang FG, Liu DM, Xing FW (2010) Two new species of Hypodematium (Hypodematiaceae) from limestone areas in Guangdong, China. Botanical Studies 51(1): 99–106.
  • Zhou FQ, Gao CF, Zhang ZR, Li JX (1999) Studies on the morphology and anatomy of Hypodematiaceae from Shandong and its taxonomic significance. In: Shing K-H (Ed.) Ching Memorial Volume.China Forestry Publishing House, 357–369.
  • Zhang GM, Iwatsuki K (2013) Hypodematium Kunze. Flora of China, Vol. 2-3. Science Press, Beijing & Missouri Botanical Garden Press, St. Louis, 535–539.
login to comment