Research Article |
Corresponding author: Yao Moan Huang ( huangym@tfri.gov.tw ) Academic editor: Blanca León
© 2017 Yi-Shan Chao, Atsushi Ebihara, Wen-Liang Chiou, Yao Moan Huang.
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:
Chao Y-S, Ebihara A, Chiou W-L, Huang Y-M (2017) Pteris latipinna sp. nov. (Pteridaceae), a new species segregated from Pteris fauriei. PhytoKeys 85: 95-108. https://doi.org/10.3897/phytokeys.85.14884
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Pteris fauriei is widely distributed in Eastern Asia and has high morphological variation. Some morphologically similar plants related to this species are difficult to distinguish. We showed that the new Pteris species from Taiwan, previously identified as P. fauriei, can be morphologically distinguished by its wide pinnae, larger terminal pinnae than the lateral pinnae in sterile fronds, and triangular basal segments of the lateral pinnae. It was confirmed that this species is phylogenetically separated from the other East Asian Pteris species, except for a morphologically distinct species P. arisanensis, by means of chloroplast genes, rbcL and matK. The new species is named as Pteris latipinna sp. nov., referring to its wide pinnae. Here, we provide a key to facilitate the identification of the morphologically similar Pteris species in Asia. The morphological descriptions, images, ecology, and distribution are also presented.
Pteris , Pteris fauriei , Pteris latipinna , Taiwan, taxonomy
Pteris fauriei Hieron. is widely distributed in Eastern Asia. Two varieties of P. fauriei have been confirmed, and both varieties have different cryptic characteristics and prefer different niches. Pteris fauriei var. fauriei, apomictic and triploid (2n = 87), usually has herbaceous laminae and prefers cooler sites; P. fauriei var. minor Hieron., sexual and diploid (2n = 58), usually has coriaceous laminae and is found in warmer sites (
Pteris fauriei and morphologically similar Pteris species are phylogenetically close.
In this study, we clarified the morphological and phylogenetic characteristics of the undescribed Pteris plants, in comparison with P. fauriei, P. natiensis, and related bipinnatifid Pteris species from East Asia, including P. wulaiensis C.M. Kuo endemic to Taiwan; P. arisanensis Tagawa, P. biaurita L., P. kawabatae Sa. Kurata, P. kiuschiuensis Hieron., and P. oshimensis Hieron. distributed in China and Japan; and P. boninensis H. Ohba, P. laurisilvicola Sa. Kurata, P. satsumana Sa. Kurata, and P. yakuinsularis Sa. Kurata endemic to Japan (
We examined type materials of morphologically similar taxa, including P. fauriei var. fauriei (in herbaria B, BM, KYO, MO, P), P. fauriei var. minor (in herbaria B, BM, KYO, P), and P. natiensis (in herbaria KYO, P). Several morphologically similar species in neighboring areas were also compared, including P. arisanensis, P. biaurita, P. boninensis, P. kawabatae, P. kiuschiuensis, P. laurisilvicola, P. oshimensis, P. satsumana, P. wulaiensis, and P. yakuinsularis.
To clarify the phylogenetic relationships of the undescribed plants, 34 other Pteris taxa with bipinnatifid laminae were sampled. Three Pteris species, P. grevilleana, P. longipinna, and P. venusta, were used as outgroups. These bipinnatifid and outgroup species belong to clades A1 and A2, respectively, according to the phylogenetic tree of Pteris (
Maximum likelihood (ML) analyses were performed using GARLI v.2.0.1019 (
The distinct morphologies that distinguished the undescribed species from other bipinnatifid Pteris species are its wide pinnae, up to 7 cm wide, and fewer pairs of lateral pinnae, only 2–5 pairs (Fig.
An endemic species in Japan, Pteris natiensis (illustrated by holotype, KYO, Fig. S3), also has sterile fronds with slightly larger terminal pinnae than the lateral pinnae. Its pinnae are slightly narrower than those of the undescribed species (3–5 cm vs. 3–7 cm), and the basal pinna-segments are adnate to the rachis whereas they are not adnate to the rachis in the undescribed species (Table
Morphological comparisons among Pteris latipinna Y.S.Chao & W.L.Chiou, sp. nov., P. fauriei var. fauriei, P. fauriei var. minor, and P. natiensis.
Species/Characteristics | P. latipinna | P. fauriei var. fauriei | P. fauriei var. minor | P. natiensis |
---|---|---|---|---|
Lamina size | 15–45 cm long, 15–40 cm wide; length/width ratio about 1 | 15–40 cm long, 10–35 cm wide; length/width ratio 1.2–1.5 | 10–30 cm long, 10–25 cm wide; length/width ratio about 1 | 15–40 cm long, 10–35 cm wide; length/width ratio about 1.1–1.2 |
Number of lateral pinnae of sterile fronds | 2–3(4) pairs | 2–7 pairs | 2–5 pairs | 2–5 pairs |
Lateral pinnae of sterile fronds | Slightly incurved | Straight | Straight | Incurved |
Petiolule | Sessile or short-petiolate. Most basal pinna-segments free to the rachis, sometimes adnate | Sessile or short-petiolate. Basal pinna-segments free to the rachis | Sessile or short-petiolate. Basal pinna-segments free to the rachis | Sessile. Basal pinna-segments adnate to the rachis; except basal pinnae |
Basal segment of lateral pinnae | Triangular | Falcate | Falcate | Falcate |
Terminal pinna size of sterile fronds | Distinctly wider than lateral pinnae except basal ones | Smaller than lateral pinnae | Smaller than lateral pinnae | Almost the same size as lateral pinnae |
Pinna shape | Ovate-lanceolate, distinctly narrowed at base | Lanceolate, not narrowed at base | Lanceolate, not narrowed at base | Ovate to lanceolate, more and less narrowed at base |
Width of lateral pinna | 3–7 cm | 2–3.5 cm | 1–3 cm | 3–5 cm |
Genetic data and the accession numbers of the sequences are listed in Appendix
The phylogenetic tree (Fig.
Both morphological and DNA characteristics support that this taxon is a new species, rather than a variety of P. fauriei. Here, we describe the new species and delimitate P. fauriei var. fauriei and P. fauriei var. minor. The morphology of the new species is presented in Fig.
TAIWAN. Hsinchu County: Zhudong Town, Wuchihshan, 3 March 2013, Y.-S. Chao 2092 (holotype TAIF!, isotype TAIF!, TNS!).
Rhizomes short, ascending, apex scaly; scales linear lanceolate, 1–4 mm long, 0.2–0.5 mm wide, concolorous, dark brown, entire, apex long-acuminate. Fronds clustered, 30–100 cm long, nearly monomorphic. Sterile fronds 30–70 cm long; stipes green, 2–4 mm thick, 10–30 cm long, base with persistent and scattered scales; grooved on the adaxial side; laminae widely ovate, 15–45cm long, 15–40 cm wide, bipinnatifid; 2–3(4) pairs lateral pinnae, pinna angle against rachis 60–70°, straight, basal pinnae with one pair of exaggerated basiscopic pinnules, terminal pinnae distinctly longer and wider than the lateral except basal ones; pinnae ovate-lanceolate, distinctly narrowed at base, pectinate, 8–21 cm long, 3–7 cm wide, sessile or short-petiolate, apex caudate, 1–4 cm long. Basal segments of the lateral pinnae triangular, the other segments of pinnae falcate, 4–9 mm wide, apex obtuse, margins entire; veins forked, free. Fertile fronds 50–105 cm long; stipes 25–55 cm long; laminae ovate to widely ovate, 20–50 cm long, 20–35cm wide, bipinnatifid; 3–5 pairs lateral pinnae, slightly incurved or straight; terminal pinna usually wider than the lateral; pinnae 8–20 cm long, 2–6 cm wide, 1–4 cm long; segments of pinnae 4–6 mm wide, apex acute or obtuse. Sori along pinna margins, protected by pseudoindusia; spore number 32; spores tetrahedral, tan.
TAIWAN. Hsinchu County: Guanxi, Chike Mt., P.-F. Lu 24585, 24586 (TAIF); Jianshi, P.-F. Lu 25108 (TAIF); Pawushan, P.-F. Lu 26666, 26673 (TAIF); Shuitien Logging Trail, L.-Y. Kuo 01 (TAIF). Miaoli County: Sintikusyu, komokwan, Yaiti Simada 5175A (HAST).
Taiwan (Fig.
In shaded places, understory of evergreen broad leaf forests, below 1,000 m in elevation.
The specific epithet ‘latipinna’ refers to its wide pinnae.
We investigated the distribution of P. latipinna Y.S.Chao & W.L.Chiou, sp. nov. in Taiwan. To date, only a few small populations are recorded. However, the available information is inadequate to support the assessment of its extinction risk. According to the
A new species, P. latipinna Y.S.Chao & W.L.Chiou, sp. nov., growing understory of forests in Taiwan was found and identified in this study. Pteris latipinna is the largest species among the bipinnatifid Pteris species with single-axis in Taiwan. There were 29 Pteris species recorded in the Flora of Taiwan (
Although the ploidy of P. latipinna is not known, with the similar morphology and apomitic reproductive mode, it is inferred that those species possibly evolved through a complex reticulate hybridization-polyploidization speciation. Those apomicitic Pteris species have also been suggested with possible hybrid origins (
In this study, taxa in Clade I and Clade II compose Pteris fauriei complex because they are morphologically similar and phylogenetically close with Pteris fauriei. All of them are distributed in Asia, mostly in Japan and Taiwan. Interestingly, distributions of most of those species are limited: Pteris latipinna and P. wulaiensis are endemic in Taiwan; P. boninensis, P. natiensis, and P. yakuinsularis are endemic in Japan (
The traits useful for separating P. latipinna from the similar species are used in a key for identification of this species as shown below.
1 | Stipes <2 mm thick | 2 |
2 | Pairs of lateral pinnae 4–6; basal pinnae shorter or equal to the second basal ones; pinnae narrowest at base | P. wulaiensis |
2' | Pairs of lateral pinnae 6–11; basal pinnae longer than the second basal ones; pinnae widest at base | P. oshimensis |
1' | Stipes 2.5–4 mm thick. | 3 |
3 | Laminae widely lanceolate; ratio of length to width approximately 3:2 | 4 |
4 | Laminae bipinnatifid; the segments extending to 2/3–4/5 of the way toward the costae; venation free or with costal areolae | 5 |
5 | Costal areolae arched, few triangular, connective veins with free veinlets. | P. biaurita |
5' | Costal areolae triangular or absent; if present, connected by a pair of furcated veinlets | P. arisanensis |
4' | Laminae bipinnatisect; the segments extending almost to the costae; venation completely free, no costal areolae | 6 |
6 | Pinnae caudate with long tail 2–4 cm. | P. boninensis |
6' | Pinnae acute or caudate with short tail 0.5–2 cm | 7 |
7 | Scales at stipe base caducous; pinnae sessile | P. laurisilvicola |
7' | Scales at stipe base persistant; pinnae often stalked | P. yakuinsularis |
3' | Laminae widely ovate, ratio of length to width approximately 5:4 | 8 |
8 | Pinnae sessile except basal ones, with basal pinna-segments adnate to the rachis, pinna angle against rachis nearly 90°, incurved | 9 |
9 | Pinnae sometimes suddenly wider at base; segments oblong with rounded apex | P. kawabatae |
9' | Pinnae not wider at base; segments falcate with obtuse apex | 10 |
10 | Pinnae nearly oblong, equally wide, 2–3 cm wide | P. kiuschiuensis |
10' | Pinnae ovate-lanceolate to lanceolate, widest at middle, 3–6 cm wide. | 11 |
11 | Lateral pinnae 5–6 pairs, pinnae 3–4 cm wide, terminal pinna-segments long, >1 cm | P. satsumana |
11' | Lateral pinnae 2–5 pairs, pinnae 3–6 cm wide, terminal pinna-segments short, <0.5 cm | P. natiensis |
8' | Pinnae stalked to sessile, without basal pinna-segments adnate to the rachis, pinna angle against rachis 60–70°, straight | 12 |
12 | Basal segments of lateral pinnae triangular | P. latipinna |
12' | Basal segments of lateral pinnae falcate | (P. fauriei) 13 |
13 | 64 spores per sporangium; laminae coriaceous | P. fauriei var. minor |
13' | 32 spores per sporangium; laminae herbaceous | P. fauriei var. fauriei |
The authors thank Pi-Fong Lu, for her assistance in collecting plant samples, and Dr. Chuan-Kuei Liao for illustration drawings. The curators of herbaria B, BM, HAST, KYO, MO, P, PE, TAI, TAIF, and TNS are gratefully acknowledged for loan of specimens. This research is supported by Ministry of Science and Technology of Taiwan (MOST103-2621-B-037-001-MY2, MOST106-2311-B-037-005-MY3).
Taxon | Specimen collection number | Collection locality | GenBank accession numbers for rbcL | matK | Herbarium for voucher specimen |
---|---|---|---|---|---|
P. setulosocostulata | Y.-S. Chao 1146 | Taiwan | KF289634 | KF289501 | TAIF |
P. keysseri | Y.-S. Chao 1403 | Philippines | KF289640 | KF289510 | TAIF |
P. mucronulata | Y.-S. Chao 1410 | Philippines | KF289641 | KF289511 | TAIF |
P. pacifica | P.I. Forster 27643 | Australia | KF289647 | KF289517 | MEL |
P. kawabatae | Y.-S. Chao 1637 | Vietnam | KF289655 | KF289525 | TAIF |
P. giasii | C. R. Fraser-Jenkins 30176 | Bangladesh | KF289660 | KF289530 | TAIF |
P. kathmanduensis | C. R. Fraser-Jenkins FN35 | Nepal | KF289663 | KF289533 | TAIF |
P. otaria | C. R. Fraser-Jenkins FN26 | India | KF289666 | KF289536 | TAIF |
P. roseililacina | C. R. Fraser-Jenkins FN31911 | Nepal | KF289669 | KF289539 | TAIF |
P. biaurita | P.-F. Lu 17285 | Taiwan | KF289676 | KF289546 | TAIF |
P. argyraea | C. R. Fraser-Jenkins FN145 | India | KF289684 | KF289554 | TAIF |
P. aspericaulis | C. R. Fraser-Jenkins FN36 | India | KF289685 | KF289555 | TAIF |
P. assamica | C. R. Fraser-Jenkins FN5 | Nepal | KF289686 | KF289556 | TAIF |
P. khasiana | C. R. Fraser-Jenkins FN129 | India | KF289688 | KF289558 | TAIF |
P. praetermissa | C. R. Fraser-Jenkins FN64 | India | KF289692 | KF289562 | TAIF |
P. subindivisa | C. R. Fraser-Jenkins FN266 | Bhutan | KF289700 | KF289570 | TAIF |
P. asperula | Y.-C. Liu 9870 | Philippines | KF289702 | KF289572 | TAIF |
P. dataensis | Y.-C. Liu 9973 | Philippines | KF289703 | KF289573 | TAIF |
P. catoptera | G. Rouhan 301 | Madagascar | KF289714 | KF289584 | P |
P. humbertii | F. Rakotondrainibe 5965 | Madagascar | KF289718 | KF289588 | P |
P. confusa | Y.-M. Huang 20061128-A | India | KF289726 | KF289596 | TAIF |
P. flava | M. Kurutok 23 | Sabah | KF289731 | KF289601 | KEP |
P. perrottei | C. R. Fraser-Jenkins FN215 | Nepal | KF289736 | KF289606 | TAIF |
P. grevilleana | Y.-S. Chao 770 (diploid) | Taiwan | HM582644 | KF289484 | TAIF |
P. venusta | Y.-S. Chao 873 | Taiwan | HM582650 | KF289486 | TAIF |
P. longipinna | P.-F. Lu 11383 | Taiwan | HM582603 | KF289495 | TAIF |
P. laurisilvicola | Y.-S. Chao 1848 | Japan | KF289738 | KF289608 | TAIF |
P. kiuschiuensis | Y.-S. Chao 1852 | Japan | KF289739 | KF289609 | TAIF |
P. satsumana | Y.-S. Chao 1853 | Japan | KF289740 | KF289610 | TAIF |
P. oshimensis | Y.-S. Chao 1881 | Japan | KF289741 | KF289611 | TAIF |
P. yakuinsularis | Y.-S. Chao 1906 | Japan | KF289742 | KF289612 | TAIF |
P. boninensis | Y.-S. Chao 1941 | Japan | KF289743 | KF289613 | TAIF |
P. natiensis | Y.-S. Chao 1835 | Japan | KF289744 | KF289614 | TAIF |
P. arisanensis | Y.-S. Chao 1621 | Vietnam | KF289677 | KF289547 | TAIF |
P. latipinna | P.-F. Lu 24585 | Taiwan | MF416317 | MF416323 | TAIF |
P. latipinna | P.-F. Lu 25108A | Taiwan | MF416318 | MF416324 | TAIF |
P. latipinna | P.-F. Lu 25108B | Taiwan | MF416319 | MF416325 | TAIF |
P. wulaiensis | P.-F. Lu 26667-1 | Taiwan | MF537503 | MF537504 | TAIF |
P. fauriei var. minor | Y.-S. Chao 2078 | Taiwan | MF416320 | MF416327 | TAIF |
P. fauriei var. fauriei | Y.-S. Chao 2083 | Taiwan | MF416321 | MF416328 | TAIF |
P. latipinna | Y.-S. Chao 2092 | Taiwan | MF416322 | MF416326 | TAIF |
Figure S1.
Data type: JPEG image file
Explanation note: Type material of Pteris fauriei var. fauriei in B (B20012819).
Figure S2.
Data type: JPEG image file
Explanation note: Type material of Pteris fauriei var. minor Hieron. in B (U. Fauriei 685, B200128109).
Figure S3.
Data type: JPEG image file
Explanation note: Holotype of Pteris natiensis Tagawa in KYO (G. Koidzumi s.n. Aug. 3, 1922).
Figure S4.
Data type: JPEG image file
Explanation note: Holotype of Pteris arisanensis Tagawa in KYO (U. Fauriei 603).
Figure S5.
Data type: JPEG image file
Explanation note: Holotype of Pteris wulaiensis C.M. Kuo in TAI (S.-J. Moore4383, TAI283138).