Stellaria pentastyla (Caryophyllaceae), a new species from Yunnan (China) Author Wang, Wen-Qiao Author Xu, Han-Feng College of Life Sciences, Sichuan University, Chengdu 610065, China Author Shen, Kang-Long Author Su, Zhi-Wei Institute of Marine Drugs, Guangxi University of Chinese Medicine, Nanning 530200, China Author Ma, Zhong-Hui text Phytotaxa 2020 2020-03-04 435 1 69 75 http://dx.doi.org/10.11646/phytotaxa.435.1.9 journal article 10.11646/phytotaxa.435.1.9 1179-3163 Stellaria pentastyla W.Q. Wang, H.F. Xu & Z.H. Ma , sp . nov . ( Figs. 2–3 ). Type:— CHINA . Yunnan : Lushui, growing on the side of road, elev. ca. 3102 m , 25°58’26”N , 98°40’44”E , 8 June 2017 , Xu & Mou YN0014 ( holotype GAUA!, isotypes IBSC!). Diagnosis: — S. pentastyla is similar to S. palustris and S. graminea , but differs from the latter two species by having 5 styles (vs. 3 styles) and shorter leaves ( 10–13 mm vs. 20–45 mm and 5–50 mm ). In addition, S. pentastyla is similar to S. patens , but can be distinguished from the latter by having 5 styles (vs. 3 styles) and glabrous plant (vs. all plant with long filiform hairs). S. pentastyla shares some common features with S. lanipes , but differs from the latter by having 5 styles (vs. 3 styles), glabrous nodes (vs. densely white lanate on the nodes), sessile leaves (vs. proximal leaves with very short petiolate). TABLE 3. Morphological comparison between S . pentastyla and related species. Differential characters are underlined.

S. pentastyla	S. palustris	S. graminea	S. lanipes	S. patens	M. aquaticum
Stems	15–23 cm long, glabrous	10–35 cm long, glabrous	10–30 cm long, glabrous	15–25 cm long, nodes densely white lanate	10–40 cm long, long filiform hairs	50–80 cm long, apically glandular hairy
Leaves	linear, 10–13 × 0.8–1 mm, glabrous	linear to lanceolate, 20–45 × 2–4 mm, margin papillose	linear to linear-lanceolate, 5–50 × 1.5–4 mm, glabrous	sessile or proximal leaves very shortly petiolate, narrowly lanceolate or linear-lanceolate, 6–20 × 2–5 mm, abaxially white lanate at midvein	linear or linear-lanceolate, 10–25 × 2–5 mm, both surfaces with long filiform hairs	proximal leaves petiolate, pubescent or glabrous, base rounded or subcordate, 2.5–5.5 × 1–3 cm
Bracts	lanceolate, 3–4 mm, glabrous	white, lanceolate to ovate- lanceolate, 3–7 mm, glabrous	lanceolate, 2–5 mm, glabrous	linear-lanceolate, smaller than leaves, herbaceous	ovate-lanceolate, 4–5 mm, with long filiform hairs, margin broadly membranous	leaflike, margin glandular hairy
Pedicels	0.6–1 cm, glabrous	7–10 cm, glabrous	0.5–2.5 cm, glabrous	0.7–2.5 cm, white lanate, hairs dense distally	0.5–1 cm, with dense long filiform hairs	1–2 cm, densely glandular hairy
Sepals	sepals 5, ovate-lanceolate, 3–4 mm	sepals 5, ovate-lanceolate, 4–7 mm	sepals 5, green, lanceolate or narrowly lanceolate, 4–4.5 mm or longer, shiny	sepals 5, lanceolate, 2.5–3 mm	sepals 5, ovate-lanceolate or lanceolate, 5–7 mm, outside with white filiform hairs, margin narrowly membranous	sepals 5, ovate-lanceolate, 4–5 mm, abaxially glandular pubescent, margin narrowly membranous
Petals	petals 5, slightly shorter than sepals	petals 5, 4–7 mm, subequaling or slightly longer than sepals	petals 5, slightly shorter or longer than sepals	absent	petals 5, shorter than or subequaling sepals	petals 5
Styles	5	3	3	3	3	5

FIGURE 2. A. Flowering plant; B. Petals; C. Sepals; D. Styles; E. Flowering branch; F. Flower; G. Stamens; H. Immature seeds. Description: —Herbs perennial, glabrous, without glands. Stems tufted, slightly erect, glabrous, quadrangular, 15–23 cm tall, slender, basally branched. Leaves sessile, pinkish green, linear, 10–13 × 0.8–1 mm , both surfaces glabrous, margins glabrous, midvein conspicuous, base slightly narrowed, apex acute. Flowers few, in terminal cymes. Pedicel 0.6–1 cm , glabrous. Bracts lanceolate, glabrous, 3–4 mm , margin membranous. Sepals 5, glabrous, ovatelanceolate, 3–4 × 1–1.2 mm , abaxially with 3 conspicuous veins, margin membranous, apex acuminate. Petals 5, ca. 2/3 as long as sepals, 2-cleft nearly to base. Stamens 10, shorter than sepals. Styles 5, filiform. Ovary ovoid. Capsule ovoid-cylindric, subequaling or slightly longer than persistent sepals. Seeds numerous, black-brown, suborbicular, conspicuously rugulose. Etymology: —The specific epithet is derived from the occurring 5 styles. Phenology: —Flowering time June–July, fruiting time July–August. Distribution and habitat: — Stellaria pentastyla is currently known only from locus classicus (Gongshan in Lushui County, Yunnan Province , China ) growing on the side of road at altitude 3102m . Conservation status: —We found two populations of Stellaria pentastyla with approximately 20 individuals only in Gongshan, Lushui County, Yunnan Province , China . Lacking further data, this species is here considered as DD (Deficient Data) according to the IUCN criteria ( IUCN 2016 ).