Research Article |
Corresponding author: Xian-Chun Zhang ( zhangxc@ibcas.ac.cn ) Academic editor: Angelo Troia
© 2017 Yu-Dong Wu, Hong-Rui Zhang, Xian-Chun Zhang.
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:
Wu Y-D, Zhang H-R, Zhang X-C (2017) Selaginella guihaia (Selaginellaceae): A new spikemoss species from southern China and northern Vietnam around the Gulf of Tonkin. PhytoKeys 80: 41-52. https://doi.org/10.3897/phytokeys.80.11126
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Selaginella guihaia sp. nov. (Selaginellaceae), a new species of spikemoss from southern China and northern Vietnam around the Gulf of Tonkin (Beibu Gulf), is described and illustrated. Morphological and molecular comparisons of the new species with other similar species (S. doederleinii, S. ornata and S. trachyphylla) are provided. The morphological and molecular evidence clearly indicates S. guihaia is a distinct species. Morphologically S. guihaia differs from other species by its obviously white–margined leaves, the ventral leaves scabrous on upper surfaces throughout the basiscopic or also rarely present on upper halves, and the ovate axillary leaves.
Lycopodiophyta , lycophytes, taxonomy, new species, rbcL , ITS
Selaginella P. Beauv. (Selaginellaceae) is the largest lycophyte genus with about 700–800 species and distributed in all the continents except Antarctica (
Morphology characters were examined from the dried herbarium specimens studied from PE (herbaria acronyms according to
We downloaded 60 sequences ITS and rbcL from Genbank representing 32 species in Selaginella and those species involves the major clades of the phylogenetic analysis of Selaginella (
The ILD test results showed no obvious conflict existing between the two datasets, rbcL and ITS (P =0.02). Thus, the datasets were combined. The combined data matrix included up to 1460 nucleotides for each of the 36 taxa with 845 constant characters, 512 parsimony informative characters, consistency index (CI) = 0.56, retention index (RI) = 0.79. The three phylogenetic analyses (MP, ML, BI) inferred congruent topologies. The Best ML tree is presented in Figure
The molecular evidence showed that two samples of Selaginella guihaia were grouped together with strong support (BS =99, PP =0.99), and then formed a moderately supported clade with S. doederleinii and S. commutata Alderw.
Our phylogenetic analyses and morphological evidence reveal that the possible new taxon Selaginella guihaia is different from the morphologically similar species S. doederleinii, S. ornata and S. trachyphylla that co-occur in the same region. The overall morphology and the growth habit of S. guihaia resemble those of S. ornata, however, the former has monomorphic (vs. dimorphic) sporophylls. Furthermore, consistent with the sporophylls variations, S. guihaia and S. ornata were separately placed into two large clades in the molecular phylogenetic tree. Although S. doederleinii and S. trachyphylla were placed closely with S. guihaia in the molecular phylogenetic analysis, the distinct white-margined leaves of S. guihaia is different from both these species. The ventral leaves of S. guihaia are scabrous near the lower part of leaf epidermis but rarely on the upper part, whereas hte ventral leaves of S. trachyphylla are scabrous throughout the leaf epidermis.
The new species is similar to S. doederleinii, S. ornata and S. trachyphylla in the habit and the morphology of dorsal leaves, ventral leaves, axillary leaves and sporophylls. However, S. guihaia can be easily recognized by its obvious white–margined leaves. The white-margin is about three cells wide in S. guihaia, but it is only one cell wide in S. doederleinii, S. ornata, and S. trachyphylla.
Selaginella guihaia X.C.Zhang A Habit B Dorsal leaf C Ventral leaf D Part of main stem showing ventral leaves, dorsal leaves, and strobili E Part of main stem showing ventral leaves, axillary leaves, and strobili F Megasporophyll G Microsporophyll (Drawn by C.Z. Ji from Beijing Youth Expedition 0980, PE).
Terrestrial. Evergreen, suberect or ascending from decumbent base, 20–50 cm. Rhizophores branched from base to middle of main stem. Main stems pinnately branched from lower part upward, stramineous, 1.5–2 mm in diam. in lower part, oval or subquadrangular, glabrous; primary leafy branches 3–10 pairs, 2 or 3 pinnately branched, secondary branches once pinnately branched, tertiary branches forked, branchlets sparse, adjacent primary branches on main stem 1–6 cm apart, leafy portion of main stem including leaves 0.8–1.8 mm wide at middle, ultimate branches 3–6 mm wide including leaves. Axillary leaves on branches symmetrical, ovate, 0.9–1.7 × 1.7–3.7 mm, bases exauriculate, margins denticulate, obviously white–margined. Dorsal leaves on branches imbricate, ovate, 0.9–2.3 × 0.3–0.9 mm, carinate, base cuneate or obliquely subcordate, margins denticulate, obviously white–margined, apices acuminate to aristate, parallel to axis. Ventral leaves on branches contiguous or overlapping, slightly ascending, oblong–falcate, 2.1–4.4 × 0.8–1.9 mm, upper surfaces on lower scabrous halves of the laminae or also rarely scabrous on upper half; basiscopic base margin entire, margin subentire, denticulate at base; acroscopic base rounded, overlapping stem and branches, margin denticulate in basal half, obviously white–margined. Strobili solitary or in pairs, terminal, compact, tetragonal, 0.8–1.4 × 0.4–0.8 mm; sporophylls monomorphic, ovate–triangular, carinate, margins denticulate, obviously white–margined, apices acuminate; sporangia pale yellow to pale brown; megasporangia spherical; microsporangia elliptic–oblong, relatively thick, marginal cells differentiated; megaspores whitish, microspores pale yellow.
China. Guangxi: Ningming, 31 Dec 2015, X.C.Zhang & al.7879 (PE); Ningming, 1 Jan 2016, X.C.Zhang & al. 7886 (PE), X.C.Zhang & al. 7887 (PE), X.C.Zhang & al. 7899 (PE), X.C.Zhang & al. 7900 (PE); Shangsi, 17 Sep 2009, Mt. Shiwandashan, 600 m, R.H.Jiang 059 (PE); Shangsi, Mt. Shiwandasahn 10 Jun 2009, 380m, S.Y. Dong 2932 (IBSC); Fangchenggang, Fulong Village, Mt. Pinglong, 360 m, 19 Sep 2009, R.H. Jiang 145 (PE); Fangchenggang, Nale Village, 250 m, 20 Sep 2009, R.H.Jiang 174 (PE); Shangsi, 22 Sep 2009, Mt. Shiwandashan, 680 m, R.H.Jiang 220 (PE); Fusui, Lucheng, 200–370 m, 26 Apr 1957, S.Q. Chen 12074 (PE); Shang–sze (= Shangsi), Shap Man Taai Shan (= Mt. Shiwandashan), 11–30 Jul 1934, W.T.Tsang 23870 (BM); Hainan: Baisha, Yinggeling, 1000 m, 27 Aug 2005, S.Y.Dong 1450 1464 (PE). Vietnam: Tien–yen, Kau Nga Shan and Vicinity, 23–30 Sep 1940, W.T.Tsang 30553 (PE); Chuk–phai, Ha–coi, Taai Wong Mo Shan and Vicinity, W.T.Tsang 29052 (P); Dam–ha, Sai wong Mo Shan, 18 Jul – 9 Sep 1940, W.T.Tsang 30273 (P); Tien–yen, Kau Nga Shan and Vicinity, 23 Sep – 7 Oct. 1940, W.T.Tsang 30582 (P); Chuk–phai, Ha–coi, Taai Wong Mo Shan and Vicinity, 18 Nov – 2 Dec 1936, W.T.Tsang 27196 (P); Tonkin, Kau Nga Shan and vicinity, Sept. 23 – Oct. 7. 1940, W.T.Tsang 30582 (B).
Widely distributed in southern China (Guangxi and Hainan) and northern Vietnam around the Gulf of Tonkin (Beibu Gulf), growing in evergreen broad–leaved forests at 250 to 1000 m a.s.l. (Figures
The specific epithet “guihaia” alludes to the ancient Chinese name for the remote geographic region where the species occurs.
We evaluated the conservation status of Selaginella guihaia according to the
1 | Sporophylls dimorphic, dorsal sporophylls longer than ventral ones; megaspores reddish brown | S. ornata |
– | Sporophylls monomorphic, dorsal sporophylls the same length as the ventral ones; megaspores whitish | |
2 | Ventral leaf upper surfaces glabrous; basiscopic base slightly dilated; microspores yellow-orange | S. doederleinii |
– | Ventral leaf upper surfaces scabrous; basiscopic base entire; microspore pale yellow | |
3 | Leaves with obvious white margin (three cells wide); ventral leaves scabrous on upper surfaces only on the basiscopic halves (rarely also on upper halves); axillary leaves ovate | S. guihaia |
– | Leaves without obvious white margin (only one cell wide); ventral leaves scabrous on upper surfaces throughout the leaf surface; axillary leaves narrowly ovate to triangular | S. trachyphylla |
This study was supported by the National Natural Science Foundation of China (31670205). We would like to thank the three reviewers for their valuable comments and suggestions.
Plant materials used in this study. Information is presented in the following order: taxon name, locality (if available), collection number (if available), ITS GenBank accession number, rbcL GenBank accession number, references (if available). –, sequences not available. *, sequences obtained in this study.
Selaginella albociliata P. S. Wang, KT161648, KT161379. Selaginella amblyphylla Alston, KT161650, KT161381. Selaginella biformis A. Braun ex Kuhn, KT161664, KT161396. Selaginella bisulcata Spring, KT161674, KT161406. Selaginella braunii Baker, KT161685, KT161419. Selaginella commutata Alderw., KT161693, KT161430. Selaginella deflexa Brackenridge, AF418999, AF093253. Selaginella delicatula (Desv.) Alston, KT161699, KT161441. Selaginella doederleinii Hieron., CHINA, Guizhou, X.–C. Zhang et al. 7113 (PE), KY06835*, KY068356*. X.–C. Zhang et al. 7880 (PE), KY068357*, KY068352*. Selaginella douglasii (Hook. & Grev.) Spring, –, AF419049. Selaginella guihaia X.C. Zhang, CHINA, Guangxi, X.–C. Zhang 7879 (PE), KY068358*, KY068353*. X.–C. Zhang 7887 (PE), CHINA, Guangxi, KY068359*, KY068354*. Selaginella helferi Warb., KT161723, KT161470. Selaginella heterostachys Baker, KT161729, KT161480. Selaginella kraussiana A. Braun. KT161746, KT161498. Selaginella lepidophylla (Hook. & Grev.) Spring, AF419002, AF419051. Selaginella mairei Levl., KT161764, KT161518. Selaginella megaphylla Baker, KT161768, KT161524. Selaginella moellendorffii Hieron., KT161777, KT161531. Selaginella nipponica Franch. et Sav., KT161786, KT161542. Selaginella ornata Spring, CHINA, Guizhou, X.–C. Zhang et al. 7082 (PE), KY068360*, KY068355*. Selaginella pallidissima Spring, KT161796, KT161556. Selaginella pennata Spring, KT161798, KT161558. Selaginella picta A. Braun ex Baker, KT161800, KT161561. Selaginella pulvinata (Hook. et Grev.) Maxim., KT161811, KT161576. Selaginella remotifolia Spring, KT161814, KT161580. Selaginella repanda (Desv.) Spring, KT161816, KT161582. Selaginella roxburghii (Hook. & Grev.) Spring, –, EU140945. Selaginella sanguinolenta (L.) Spring, KT161822, KT161589. Selaginella scabrifolia Ching & C.H.Wang, KT161824, KT161593. Selaginella selaginoides (L.) Link, AF419000, AF419048. Selaginella sibirica (Milde) Hieron., AF419032, AF419076. Selaginella superba Alston, KT161842, KT161616. Selaginella tamariscina (P.Beauv.) Spring, –, AB574655. Selaginella trachyphylla A.Braun ex Hieron., –, KT161620. Selaginella vardei Levl., KT161853, KT161628.