Triplostegia alpina S.L.Tan

Tan, Shaolin, Fu, Qingli, Mo, Zhiqiong, Sun, Yanan, Fang, Yi & Yang, Boyun, 2024, Triplostegia alpina (Caprifoliaceae): a new species from Southwest China, Phytotaxa 640 (3), pp. 284-292 : 286-290

Triplostegia alpina S.L.Tan sp. nov. (Chinese name: ṘNJĀţ)

Diagnosis: Triplostegia alpina is morphologically similar to T. glandulifera in terms of flower shape, color, and size, as well as petiolate leaves. However, it can be distinguished from T. glandulifera by its one to three white, glabrous lateral taproots, serrated leaves, and slightly hooked involucel apex that is purple in color rather than the significantly hooked involucel apex that is crystal greenish-white in T. glandulifera . Additionally, T. alpina differs from T. grandiflora in having a slender bifurcated to tetrafurcated taproot, a non-rugged surface on the main taproot, one to three slender lateral taproots, petiolate leaves instead of sessile ones, and smaller corollas.

Type: CHINA. Yunnan, Lijiang, Yulong Mountain , and elevation 2737 m, August 30, 2020, TSL202293 (Holotype: JXU!) .

Morphology: Perennial herb, erect, 10–63 cm tall. Taproot bifurcate, trifurcate, or tetrafurcate. Main taproot in brown, slightly fleshy, non-rugged on the surface, with fine roots; lateral taproots are white, slender, glabrous, with a purple coloration at the upper end. Stem solitary, simple, sparsely white villous. Leaves opposite, petiolate, petiole 5–40 mm. Basal leaves dense, rosulate; cauline leaves decussate; upper leaves gradually smaller and becoming bractlike, sessile. Leaf blade obovate, 15–92 mm long and 11–33 mm wide, with base cuneate, apex rounded, serrated, both leaf surfaces sparsely villous. Inflorescences thyrsoidal, branches compact to elongate, all parts (except corolla) densely villous and glandular hairy. Calyx reduced, 4-lobed. Corolla white, or rose at the apex, funnelform, 5-lobed, 1.1–2.2 mm long, outside sparsely villous; lobes subequal, about half as long as total length of corolla, apex obtuse. Stamens 4, equal in length, alternate with corolla lobes, slightly exserted. Style solitary, equal in length with stamens; stigma capitate. Achenes enveloped by urceolate involucels; involucels 3–4 mm long in fruit, glandular hairy, 4-lobed; lobes long acuminate, slightly hooked at apex, apex in purple. Seeds subglobose; endosperm copious; embryo small.

Etymology: The species is named for the high elevation it inhabited. It can inhabit 4342 m, more than 1000 m higher than the elevation limit of its two congeners.

Vernacular name: Chinese mandarin: gao shan shuang shen (ṘNJĀţ)

Phenology: Flowers and fruits from July to October.

Distribution: Triplostegia alpina is distributed in the Hengduan Mountains Region and east Himalaya.

Habitat: It grows in a variety of habitats including coniferous forest or mixed coniferous broad-leaved forest understories, forest margins, slopes, roadsides, along streams, alpine meadows; 1800–4342 m a.s.l.

Conservation status: Even if many newly described taxa are considered threatened according to the IUCN (2022) categories and criteria (e.g., Sağiroğlu & Eker 2021), in some cases they are considered not or near threatened (LC/NT) (e.g., Perrino et al. 2018). According to the available data on distribution, habitat and threats, we consider Triplostegia alpina as not threatened (LC, Least Concern).