Paris caojianensis B.Z.Duan & Y.Y.Liu, 2017

Paris caojianensis B.Z.Duan & Y.Y.Liu View in CoL , sp. nov. ( Figs.1 View FIGURE 1 , 2 View FIGURE 2 )

P. caojianensis is similar to P. mairei , but some filaments of stamens are adnate to the petals, others stamens are free; free portion of connective is 0.2–0.4 cm (not 0.05–0.1 cm). The number of stamens is more than petals, and the stamens are typically arranged in a single whorl. The petals are dark purple in the upper part, and green in the part near to sepals. In addition, petioles are 0.1–0.8 cm (not 0–0.4 cm) long, and plants are glabrous (not papillose-pubescent).

Type:— China, Yunnan, Yunlong County: Caojian township, Songpojiao village , under Paris plantation areas on hill slopes, 2160 m, 25°40’18”N, 99°8’19”E, 11 August 2016, B.Z. Duan & Y.Y. Liu 055 (holotype, DLU!) GoogleMaps .

Herbs perennial, glabrous, oblique or erect. Stem 1, 40–67 cm tall, 0.4–0.7 cm in diameter, base thickness with purplish red. Rhizome horizontal, dark brown outside, and white inside, well developed root system, 2.5–8.5 cm long, 0.4–3.4 cm in diameter, varying in width and with apparent segmentation. Leaves 6–13 in a terminal whorl at the apex of the stem, usually 9, elongate-elliptic to lanceolate, margins entire or micro-undulate, slightly ciliate, 5–13 × 1.7–3 cm, green adaxially without purple spot and pale green abaxially, apex attenuate, base attenuate to petiole, or cuneate; midvein of leaves prominent and adaxially depressed, abaxially raised, 5 to 8 pairs of lateral veins, the first pair subbasal, straight to the edge of the leaf margin, from the second pair the lateral veins start grow alternate or opposite in the near one-third of the midvein, arching until becoming almost invisible in the final part. Petiole purple, length 0.1– 0.8 cm, width 0.1–0.2 cm, some leaf sessile. Flowers solitary, pedicel green proximally, purplish distally, 10–20 cm × 0.1–0.4 cm. Sepals 3 to 7, usually 5, green adaxially, pale green abaxially, separate from each other, elongated-elliptic to lanceolate, 4–6 × 0.7–1.4 cm, apex long acuminate. The petals (4 to 7, usually equalling the number of sepals) close to the sepals are green, the remaining parts are purple, filamentous, 1.5–4.5 cm long, about 0.2 cm wide, shorter than sepals. Stamens in one whorl, 1.0– 2.6 cm long, persistent, some filaments of stamens are adnate to the petals, others are free; the number of stamens is more than petals. Filaments green; anthers 0.5–1.2 cm long, yellow; the free portion of connective is dark purple, 0.2–0.4 cm long, columnar. Ovary green with 1 locule, with marked ridges, 1–3 cm long, placentas 4–6 with yellow, anatropous ovules numerous, ovoid. Styles and stigmas are purple black, 0.3–0.6 cm long, 4 to 6, separated and rolled; the stylar base is deep purple at flowering, turning to yellowish-white in fruit; inflated into short angles and covered on the top of ovary. Capsule globose, 1.5–4.2 cm in diameter, with 4 to 6 longitudinal winged ridges, yellowish green (green when immature, yellow when ripening), irregularly ripening between ridges. Seeds numerous, with red sarcotesta, ovoid, smooth, juicy and fleshy; endotesta white, approximately 0.4 cm in diameter.

Phenology:—Flowering from April to June and fruiting from July to September.

Etymology:—The specific epithet “ Caojianensis ” is named after the place where the species was first discovered.

Distribution:—The new species is found in Yunlong County, Yunnan Province, China. We found the population during the field investigation in the hill slopes, Songpojiao villiage, Caojian Township. We suspect that the new species possibly occurs also in the contiguous Gaoligong Mountain.

Taxonomic relationships:— Paris caojianensis belongs to P. subg. Daiswa ( Rafinesque 1838: 18, Li 1984: 356) due to its thick rhizome, green ovary with one locule, juicy sarcotesta, showing 4 to 6 green longitudinal ridges. In particular, the new species shows affinity with P. mairei . However, all published Paris classification systems suggest that the stamens of P. mairei is two whorls ( Li 1998). This is contradictory to the morphological features of P. caojianensis . We also observed an unusual appearance, with some filaments adnate to the petals, others free.