Stellaria pentastyla W.Q. Wang, H.F. Xu & Z.H. Ma, 2020

Wang, Wen-Qiao, Xu, Han-Feng, Shen, Kang-Long, Su, Zhi-Wei & Ma, Zhong-Hui, 2020, Stellaria pentastyla (Caryophyllaceae), a new species from Yunnan (China), Phytotaxa 435 (1), pp. 69-75 : 71-73

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).

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).

Figures

FIGURE 2. A. Flowering plant; B. Petals; C. Sepals; D. Styles; E. Flowering branch; F. Flower; G. Stamens; H. Immature seeds.

FIGURE 3. Stellaria pentastyla. A. Habit; B. Inflorescence; C. Sepals; D. Flower.