Corresponding author: Tetsukazu Yahara (
Academic editor: G. P. G. del Galdo
An unknown taxon of
Yahara T, Hirota SK, Fuse K, Sato H, Tagane S, Suyama Y (2021) A new subspecies of
This study describes an additional new taxon that inhabits the mountainous area of Yakushima, an island where a variety of endemic plant taxa have been previously recorded (
Yakushima (Yaku Island) is a roughly circular island with a circumference of approximately 130 km and is located approximately 60 km south of the main island of Kyushu. Since the initial taxonomic review of 45 species of vascular plants endemic to Yakushima (
A list of samples used in the molecular phylogenetic analyses.
Scientific name | Voucher ID | Locality | Latitude, Longitude |
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JPN0029 | Itoshima, Fukuoka |
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JPN3306 | Itoshima, Fukuoka |
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JPN0573 | Yakushima, Kagoshima |
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JPN1791 | Yakushima, Kagoshima |
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JPN3046 | Mitsukaido, Ibaraki |
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JPN3106 | Itoshima, Fukuoka |
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JPN1352 | Mt. Yokogura, Kochi |
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JPN0008 | Itoshima, Fukuoka |
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JPN0069 | Itoshima, Fukuoka |
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JPN0816 | Itoshima, Fukuoka |
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JPN2119 | Mt. Shiraiwa, Miyazaki |
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JPN2998 | Osugi-dani, Mie |
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JPN0006 | Itoshima, Fukuoka |
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Total DNA was extracted from dried leaves using the CTAB method (
Maximum likelihood phylogeny based on SNPs was inferred using the RAxML 8.2.10 software (
Three chloroplast and two nuclear genomic regions were sequenced using next-generation DNA sequencing. In this regard,
The sequences of the five regions were determined using the Claident pipeline (
Multiple alignments were performed using the MAFFT 7.313 program (
All raw MIG-seq data were deposited at the DDBJ Sequence Read Archive (
A total of 15,551,282 raw reads (1,196,252 ± 87,288 reads per sample) were obtained via MIG-seq, of which 14,923,278 reads (1,147,944 ± 84,758 reads per sample) remained after quality control. Following the
Fewer shared loci were observed between
A phylogenetic tree of
A total of 64,378 reads (4,952 ± 387 reads per sample, ITS1) and 68,362 reads (5,258 ± 357 reads per sample, ITS2) were obtained. After the gaps were trimmed, the total length of the remaining sequences was 662 bp. The monophyly of
A phylogenetic tree of
A total of 23,206 reads (1,785 ± 129 reads per sample,
A phylogenetic tree of
Phylogenetic trees obtained using MIG-seq, ITS sequences, and cpDNA sequences supported the monophyly of
In Japan,
In Japan,
Japan. Kagoshima Prefecture: Yakushima, along a path to Mt. Nagata, on rocks along streams,
Herbs possibly biennial. Stems caespitose, 2.5–6 cm long, glabrous, erect in upper and middle parts, prostrate in lower parts. Leaves deciduous, sessile; blade oblong-obovate or narrowly obovate, 0.5–1 cm × 1–3 mm, glabrous, single-veined, base attenuate, apex acute, margin entire. Flowers solitary or 2–3 flowers in an axillary or terminal cyme with a ca. 6 mm scape. Pedicel 1–6 mm long, slender, glabrous. Sepals ovate-lanceolate, ca. 2.5 mm long in chasmogamous flowers, ca. 2.0 mm long in cleistogamous flowers, glabrous, apex acute. Petals of chasmogamous flowers 5, ca. 2.6 mm long, 2-cleft nearly to base; lobes oblanceolate, apex obtuse; petals absent in cleistogamous flowers. Stamens of chasmogamous flowers 3, 0.8 mm long; filaments ca. 0.4 mm long, glabrous, anthers globular, 0.4 mm in diam. Styles 2, glabrous. Capsule obovoid, 2.5 mm long, as long as sepals when mature, 2-loculated. Seeds dark brown, reniform, ca. 0.7 mm long, slightly flattened, tuberculate with raised papillae, without an appendage.
Chasmogamous flowers were observed in May, cleistogamous flowers and immature fruits were observed in July, and mature fruits and seeds were observed in September.
Yakushima, Japan (endemic). At present, this subspecies has been identified in two populations growing on rocks along streams at 1500 m elevation in the vicinity of Mt. Nagata.
The subspecific epithet is derived from its dwarf habit.
Vulnerable (
Japan. Kagoshima Prefecture: Yakushima, along a path to Mt. Nagata,
We thank Toshihiro Saito for his help with our fieldwork in Yakushima. Specimens of