Fagopyrum longzhoushanense J.R.Shao, 2017

Wang, Cheng-Long, Li, Zhi-Qiang, Ding, Meng-Qi, Tang, Yu, Zhu, Xue-Mei, Liu, Jian-Lin, Shao, Ji-Rong & Zhou, Mei-Liang, 2017, Fagopyrum longzhoushanense, a new species of Polygonaceae from Sichuan, China, Phytotaxa 291 (1), pp. 73-80 : 76-78

publication ID

https://doi.org/ 10.11646/phytotaxa.291.1.7

persistent identifier

https://treatment.plazi.org/id/03E64749-B260-FFB9-93DD-9FCFFC7FF7F3

treatment provided by

Felipe

scientific name

Fagopyrum longzhoushanense J.R.Shao
status

sp. nov.

Fagopyrum longzhoushanense J.R.Shao View in CoL sp. nov. ( Figs. 1–2 View FIGURE 1 View FIGURE 2 )

Type:— CHINA. Sichuan Province: Liangshan State, Puge County, Longzhoushan, Lobo Village, in thick growth of maize fields, 27°37′– 28°33′N, 102°25′– 103°35′E, 1878 m a.s.l., 18 September 2011, Ji-Rong Shao Ghassot 5060 (holotype, SAU!) ( Fig. 1 View FIGURE 1 ).

Diagnosis:— Affinis Fagopyro gracilipei, sed plantis omnino dense pubescentibus vel villosis, caulibus et ramis grossis, rubero-brunneis, nodis comparate densis, laminis supra tenuiter rugosis, manifeste parvopustulatis, staminibus longiis quam pistillis differt.

Description:— Plants annual, herbaceous (therophyte), 18–70 cm tall. Stems usually erect (sometimes prostrate), highly branched in the terminal part; stems and branches thick, red-brown, internodes shorter, nodes dense, densely pubescent or villous. Leaves alternate, entire on margins, with baldes greenish to reddish-brown, densely pubescent in both surfaces, rugulose and small postulate on the adaxial surface, ovate-triangular or triangular-ovate [(0.9–)1.7–6.0 × (0.7–) 1.2–5.1 cm], petioled [petioles (0.5–) 2.6–7.5 cm long]. Inflorescences racemose, axillary and terminal, 1–4 cm long. Flower with 5 perianth segments, elliptic to ovate [1.3–2.0 × 1.1–1.5(–1.8) mm], white or pink-red; bracts, when present, ovate to broadly ovate [0.7–1.4 × 0.5–1.2 cm], finely pubescent, cordate basally, short-acuminate to pungent apically, basal veins 7–9, central thick vein projecting to an acuminate apex; pedicel linear, often greenish and white; rachis 4-angled, green to brownish, white villous, finely grooved; stamens 8, 0.8–1.0 mm long, longer than pistils, styles 3, 0.5–0.6 mm long, white and glabrous, ovary with the stigma small, capitate. Achenes 2.5–3.0 × (2.0–)2.5–3.0 mm, inflated in central section, smooth, lustrous, rounded basally, persistent perianth, obtuse apically, black or blackish brown, winged along achenes angles.

Etymology:— The specific epithet refers to the name of the type locality.

Distribution and habitat:— Fagopyrum longzhoushanense is known only from wet sites in valleys and orchards or limited to the thick growth of weeds in corn fields in Puge County (Liangshan State, Sichuan Province, China). It grows at elevations 1800–1980 m a.s.l..

Phenology:— Flowering time July–October; fruiting time August–November

Conservation status:— Fagopyrum longzhoushanense is assessed here as Least Concern (LC) according to IUCN Red List criteria (IUCN, 2001). This species is known from the protected nature reserves in Longzhoushan, and it has relatively extensive distribution including the core area 96.58 km 2 and the buffer area 27.66 km 2 of Longzhoushan.

Morphological remarks ( Fig. 2 View FIGURE 2 ): — Fruits (achenes) of Fagopyrum longzhoushanense are triangular pyramidal or ovoid triangular-pyramidal, inflated in central section, rounded basally, obtuse apically. The achenes are 2.5–3.0 mm long and (2.0–)2.5–3. mm in diameter, black or blackish-brown, lustrous, winged along achenes angles, 1.8–2.5 mm. On the other hand, F. gracilipes displays fruit mostly triangular-pyramidal, and acute upper apex, 2.3–2.5 mm long and (1.5–) 1.8–2.4 mm in diameter (so being slightly smaller then F. longzhoushanense ).

Karyotype ( Table 2, Fig. 3 View FIGURE 3 ): — Fagopyrum longzhoushanense is a diploid taxon, with 16 chromosomes (2n=2x=16), with metacentric chromatid. F. gracilipes is a tetraploid taxon, with 32 chromosomes (4n=4x=32), of which 30 chromosomes are metacentric and two are submetacentric. No satellites were observed on chromosomes of either F. longzhoushanense or F. gracilipes . The relative length of chromosome from F. longzhoushanense is 10.057 – 14.751, and the ratio of longest and shortest chromosome is 1.467. The ratio of chromosome arms ranges from 1.026 to 1.667, and the average ratio is 1.289. The relative length of chromosome from F. gracilipes is 2.22–4.10, and the ratio of longest and shortest chromosome is 1.85. The ratio of chromosome arms ranges from 1.06 to 2.02 while the average is 1.28. Both of them should be assigned to category 1A according to Stebbins (1971).

Phylogenetic relationship based on the matK ( Figs. 4–5 View FIGURE 4 View FIGURE 5 ): — The lengths of matK in the currently sequenced species of buckwheats was consistent with the data reported before, which size were within 1428 bp ( Johnson & Soltis 1995).

On the basis of the results obtained ( Figs. 4–5 View FIGURE 4 View FIGURE 5 ) two major clades (marked as “A” and “B” in Fig. 4 View FIGURE 4 ) can be considered. The Group A (97% of bootstrap value) includes six Fagopyrum species [ F. tataricum Gaertn (1791: 182) , F. esculentum Moench (1794: 290) , F. cymosum Meisn (1832: 63) , F. wenchuanense J.R.Shao (2008: 929) , F. urophyllum H. Gross (1913: 21) , and F. loujishanense J.R.Shao (2015: 22) ] (see Lin 2004, Campbell 1997, Yamane 2003, Shao et al. 2011, Ohnishi et al. 1996, Hou et al. 2015). The Group B (100% of bootstrap value) contains five Fagopyrum species [ F. qiangcai D.Q.Bai (2011: 256) , F. pugense T. Yu (2010: 239) , F. gracilipes Damm. ex Diels (1900: 31) , F. densovillosum J.L.Liu (2008: 530) , and F. longzhoushanense ] (see Tang et al. 2010, Shao et al. 2011, Zhou et al. 2014, Ohnishi et al. 1996). Both the cladograms ( Figs. 4–5 View FIGURE 4 View FIGURE 5 ) show that F. longzhoushanense can be considered as separate taxon.

Diagnostic keys:— We following present key to identify the Fagopyrum species studied.

1. Plants subglabrous, stems and branches thin, green or green-brown, internodes sparser, nodes scattered; Llaf blade hirtellous or subglabrous in both the surfaces, nearly smooth surface ................................................................................................. F. gracilipes View in CoL

- Plants densely pubescent or villose; stems and branches thick, red-brown, internodes shorter, nodes dense; leaf blade densely pubescent in both the surfaces, rugulose and small pustulate............................................................................................................2

2. Achenes never winged on the angles......................................................................................................................... F. densovillosum

- Achenes winged on the angles ........................................................................................................................... F. longzhoushanense View in CoL

Paratypes:— CHINA. Sichuan: Puge County, Longzhoushan, Lobo Village, in a thick growth of maize fields,

1878 m a.s.l., 18 September 2011, Ji-Rong Shao Ghassot 5060 (SAU).

SAU

Southern Arkansas University

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