Peliosanthes planicoronata F.Z. Feng, 2024

Peliosanthes planicoronata F.Z. Feng , sp. nov. ( Fig. 1 View FIGURE 1 )

Diagnosis: —Morphologically most similar to Peliosanthes khasiana , differing in its triangular segments, orifice of the corona 1.7–2.0 mm in diam., connate filaments, style dense with verrucous protrusions.

Type: — CHINA. Yunnan province: Honghe Hani and Yi Autonomous Prefecture, Jinping Miao, Yao and Dai Autonomous County, Mengqiao Town (勐ffi乡), Xinzhai (ṁfi), in elev. 1146 m, 3 June 2021, herbarium specimen prepared from the plant cultivated in garden in Zaozhuang University on 22 April 2024 (number: Feng 20210613), Feng 20240404 (holotype: KUN!).

Description: —Herbaceous evergreen perennial plants. Rhizome short, 3–5 mm in diameter. Cataphylls greenish or purplish, oblong-ovate to triangular-lanceolate, broadly obtuse, papyraceous, up to 13 cm long. Roots yellowishbrown, wiry, 3.5–4 mm in diameter, covered with brownish root hairs. Leaves bright green adaxially, light green abaxially, erect to curved, petiolate; petiole rigid, straight or arching, 18–32 cm long, 2–2.5 mm in diameter; leaf blade narrowly to broadly elliptic, 15–25 cm long, 6–7 cm wide, glabrous, more or less coriaceous, basally cuneate and distally shortly acuminate, entire and slightly undulate along the margins; with 13–20 prominent longitudinal veins and numerous subperpendicular secondary veinlets. Inflorescence a lax raceme, 14–30 cm tall; scape ascending to straight, rigid, 6–8.5 cm long, 2–3.5 mm in diameter, light to dark violet; sterile bracts 3–5, violet to green, lanceolate, 9.5–10.2 mm long, 7–9 mm wide; rachis longitudinally finely ridged, light violet, 8–20 cm long, bearing 6–15 flowers. Floral bracts 2 at the base of pedicels, light green or violet, yellowish scarious when dry; outer bracts triangularovate, concave, acuminate, 8–9.5 mm long, 4.5–5.5 mm wide; inner ones lanceolate, much smaller. Pedicels purplish, straight to slightly arching, perpendicular to the rachis or obliquely upward-facing, terete, 5–8 mm long, 0.5–0.8 mm in diameter. Flowers solitary, widely opened and soon after fully opened, it quickly closed, yellow-green to brown on the front, green on the back, more or less speckled with violet, ca. 3cm diam.; perianth tube broadly obconical, 6.5–7.5 mm across, 2.2–2.6 mm hight, jointed at the base with articulation to the pedicel; perianth segments 6, triangular, arranged in two whorls, subsimilar, 4–5.5 mm long, 3–3.5 mm broad, outer segments slightly longer and obtuse at the apex, densely marked with purple spots. Staminal corona yellow-green, extremely flat and with minutely verrucose, densely marked with purple spots; corona 1.5–2.3 mm high, 5.5–6.3 mm in diameter, hexagonal in outline, not divided into lobes; orifice of the corona 1.7–2.0 mm in diameter; anthers in the radii of tepals, attached to the inner surface of the corona just below the orifice, dorsifixed, introrse, sessile, 1 mm long, cylindrical, longitudinally dehiscent. Pistil ca. 3 mm long, densely marked with purple spots and verrucose protrusions. Ovary semi-inferior, convex, broadly conical, 1.5 mm high, 1.5–2 mm wide in the middle part, 3-locular, each locule bearing 4–6 ovules; style 1.5–1.8 mm high, 1.1–1.5 mm wide at the base, with prominent furrows along the borders between carpels; stigmas 3, carinal, less than 0.5 mm long, occupying the apical surface of the style and not prominent beyond the style width. Seeds ca. 1.2 cm long, 0.6 mm in diameter.

Etymology: —The specific epithet refers to the flat corona.

Habitat and phenology: —Primary or secondary broad-leaved evergreen forests on rocky limestone, at elevations 1000–1500 m a.s.l.; terrestrial or lithophytic clustering herb on shady rocky slopes. Flowering in April–May.

Distribution and conservation: —Endemic to lowland limestone areas of Southern Yunnan province. Locally abundant and only found in limestone areas so far. Estimated IUCN red list status: ‘Least Concern’ (LC) ( IUCN 2022). Living plants are currently cultivated at Zaozhuang University collected from Jinping County (number: Feng 20210613).

Taxonomic relationships: — Peliosanthes planicoronata appears most closely allied to P. khasiana in having a flat corona, style with 3 intercarpellary (septal) wings and semi-inferior, but differs in segments triangular (vs. orbicular, broadly ovate or ovate), orifice of the corona 1.7–2.0 mm in diam. (vs. 2.2–2.5 mm in diam.), connate filaments (vs. distally raised at periphery of central orifice), style dense with verrucous protrusions (vs. smooth). P. planicoronata is also close to P. yunnanensis ( Fig. 2 View FIGURE 2 ) in the style with 3 intercarpellary wings. However, P. yunnanensis can be distinguished by its raised corona with shallowly lobed edges, longer anthers, ca. 2 mm long (vs. ca. 1 mm long), a smooth surface on the pistil, and a superior ovary. P. planicoronata is also similar to P. laotica , but distinguishable by its perianth segments triangular and not reflex (vs. ovate and reflex), orifice of the corona small, style with 3 intercarpellary, ovary semi-inferior (vs. ovary semi-inferior to almost inferior), style with verrucous protrusions. P. griffithii and P. planicoronata both have a flat staminal crown, but the former is unique in having a long slender stoloniform rhizome, perianth segments revolute and corona erect ( Tanaka 2018). Additionally, the leaf margins in some specimens of P. griffithii from Vietnam often with slightly serrulate ( Averyanov et al. 2016). In P. teta the corona is also flat, but flowers in clusters of 2–5 and while in P. planicoronata , the flowers are solitary.