Spiradiclis danxiashanensis R. J. Wang, 2015

Wang, Rui-Jiang, Wen, Hai-Zhen, Deng, Shu-Jun & Zhou, Lian-Xuan, 2015, Spiradiclis danxiashanensis (Rubiaceae), a new species from South China, Phytotaxa 206 (1), pp. 30-36 : 31

publication ID

https://doi.org/ 10.11646/phytotaxa.206.1.5

DOI

https://doi.org/10.5281/zenodo.13642449

persistent identifier

https://treatment.plazi.org/id/110F879A-D722-C136-BFA1-FF0C787EF84B

treatment provided by

Felipe

scientific name

Spiradiclis danxiashanensis R. J. Wang
status

sp. nov.

Spiradiclis danxiashanensis R. J. Wang View in CoL , sp. nov. ( Figs. 1 View FIGURE 1 & 2 View FIGURE 2 : A–E)

Type: — CHINA. Guangdong province: Shaoguan City, Renhua County, Mt Danxiashan, 25°01’ N, 113°44’ E, 145 m, 13 April 2011, short-styled flower, R.- J. Wang & H.- Z. Wen 1548 (holotype IBSC!, isotypes IBSC!).

Spiradiclis danxiashanensis is similar to S. guangdongensis , from which it differs in having concolorous leaves with acute to acuminate apices, 4–5(–6) pairs of secondary veins, smooth projections at the periclinal walls of leaf epidermal cells, and cymose inflorescences with (1–)2–3 flowers.

Perennial herbs, prostrate or decumbent, rooting at basal nodes; stems terete, slender, sparsely pubescent. Stipules entire or bipartite, lobes linear, 2–5 mm long.Petiole 4–12 mm long, sparsely pubescent; leaf blades ovate, 0.5–2.4 (–3.3) × 0.5–1.5 (–2) cm, base truncate to rounded, apex acute to acuminate, papery, margin densely ciliate, adaxially sparsely hispidulous, abaxially usually glabrous or subglabrous, light green, concolorous both sides; secondary veins 4–5 (–6) on each side; leaf epidermal cells irregularly polygonal on adaxial side, 62.3 × 29.3 μm, anticlinal walls sinuous, periclinal walls with large and smooth irregular projections; abaxial cells irregularly polygonal, 72.5 × 34.0 μm, anticlinal walls sinuous, periclinal walls with large and smooth irregular projections; stomata paracytic ( Fig. 3 View FIGURE 3 : A – C). Inflorescence terminal, cymose, (1–) 2–3-flowered; peduncles sparsely puberulent, 1.3–2.8 cm long; bracteoles linear, 2.5–4.3 mm long. Flowers sessile or short-pedicellate, distylous, 5-merous; pedicels (when present) sparsely puberulent, to 5.0 mm long. Hypanthium obconical, 0.5–1.5 mm long, sparsely puberulent to glabrescent; lobes lanceolate, 2.3–3.2 × 0.6–1 mm, glabrous, with inconspicuous glands at each sinus. Corolla salverform, white, subglabrous abaxially, tube 1.1–1.5 cm long, 0.6–1.5 mm wide; lobes subovate, 5.0–8.7 × ca. 3.5 mm; stamens 5; anthers oblong-linear, 1.6–3.0 mm long; stigma bilobed. Long-styled flowers: corolla tube subglabrous, densely pubescent on throat inside; stamens included, filaments adnate to the lower corolla tube, ca. 1.5 mm long; styles exserted, 1.8–2.1 cm long, stigmas capitate. Short-styled flowers: corolla tube sparsely pubescent inside but densely on throat; stamens exserted, filaments adnate to the upper portion corolla tube, 5–6 mm long; styles included, 6–9 mm long, stigmas linear. Capsules ovoid to subglobose, 1.3–1.9 mm long, with persistent calyx lobes. Seeds ca. 0.6 mm long, deep brown or black, angular. Pollen grains released in monads; isopolar; round-triangular at polar view; spheroidal, 29.3 (28.2–31.1) × 28.3 (27–30.5) μm in short-styled flowers, 27.5 (26–28.6) × 25.6 (23.5–27.7) μm in long-styled flowers, with 1.1 P / E value; 3-colporate; tectum microreticulate ( Fig. 3 View FIGURE 3 : G – L).

Distribution and habitat: —Known only from Mt Danxiashan, the type locality. It grows commonly on hill slopes in understory vegetation of secondary forests.

IUCN Conservation assessment: — Spiradiclis danxiashanensis is only known from the type locality, although it is very common under forest at the lower land area of Mt Danxiashan World Geological Park. There are no significant or plausible threats because of the strict protection. It is therefore classified as Least Concern (LC), according to the guideline 8.1 of the IUCN Standards and Petitions Subcommittee (2014).

Phenology: —Flowering in March–April and fruiting in April–July.

Additional specimens examined (paratypes): — CHINA. Guangdong province: Shaoguan city, Renhua County, Mt Danxiashan , 14 November 1973, C.- C. Huang & Y.- T. Chang 038 ( IBSC, paratype of S. guangdongensis with typo error “ 34 ”) ; ibid., September 1980, H.- S. Lo 1447 ( IBSC, paratype of S. guangdongensis ) ; Mt Danxiashan, roadside in the Zhanglaofeng Scenic Area , 113°44’ E, 25°01’ N, 103 m, 24 May 2010, R.- J. Wang 1326 ( IBSC) GoogleMaps ; Mt Danxiashan, hill slope nearby the Telpher Station , 113°44’ E, 25°02’ N, 91 m, 13 April 2011, R.- J. Wang & H.- Z. Wen 1546, 1547, 1549 ( IBSC) GoogleMaps ; ibid., 11 May 2011, R.- J. Wang & H.- Z. Wen 1592 ( IBSC) GoogleMaps ; Mt Danxiashan, hill slope nearby the entrance of Zhanglaofeng Scenic Area , 113°44’ E, 25°02’ N, 147 m, 22 April 2014, R.- J. Wang 2674, 2675 ( IBSC) GoogleMaps .

Taxonomic notes: — Spiradiclis danxiashanensis is similar to S. guangdongensis in leaf size, corolla color and shape, but differs in habit, leaf color and shape, number of secondary veins, morphological pattern of epidermal cells, and flower number per inflorescence ( Table 1). The separation of S. danxiashanensis from S. guangdongensis makes it necessary to provide an emendation to the description of S. guangdongensis ( Lo 1987) . In addition, the characters of long- and short-styled flowers are supplemented. Apparently S. danxiashanensis is also similar to S. hainanensis H. S. Lo (1987: 301) , but the latter has cordate leaf bases and densely pubescent stem, petioles, abaxial side of leaf blade, peduncles, and abaxial side of calyx. Moreover, the flowering season of S. hainanensis is in October, while S. danxiashanensis is in March and April.

R

Departamento de Geologia, Universidad de Chile

J

University of the Witwatersrand

H

University of Helsinki

Z

Universität Zürich

IBSC

South China Botanical Garden

A

Harvard University - Arnold Arboretum

C

University of Copenhagen

P

Museum National d' Histoire Naturelle, Paris (MNHN) - Vascular Plants

E

Royal Botanic Garden Edinburgh

G

Conservatoire et Jardin botaniques de la Ville de Genève

L

Nationaal Herbarium Nederland, Leiden University branch

Y

Yale University

T

Tavera, Department of Geology and Geophysics

S

Department of Botany, Swedish Museum of Natural History

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