Incarvillea uniflora H.P. Deng & Chang Y. Xia, 2021

Xia, Changying, Lan, Xiaozhong, Zuo, Youwei, Lin, Le & Deng, Hongping, 2021, Incarvillea uniflora (Bignoniaceae), a new species from Hengduan Mountains, southwest China, Phytotaxa 528 (1), pp. 52-58 : 54-57

Incarvillea uniflora H.P. Deng & Chang Y. Xia , sp. nov. Figs.1 , 2 , 3

Type:— China. Xizang: Markam County, Zongxi villages, 29° 48’ 02.74”N, 98° 42’ 43.88” E, grassland, Elev. 4061 m, 12 Dec. 2013, X. Z . Lan , L. Q . Li & J . Luo 542129130803144 LY (holotype: ISBC!) .

Diagnosis:— Incarvillea uniflora is most similar to I. himalayensis , but differs by leaves all simple (vs. usually pinnately lobed or reduce to single lobe), calyx lobes long triangular (vs. ovate to lanceolate), peduncles 6.5-16.5 cm (vs. 2.2–2.8(–4.5) cm), flowers solitary or clustered (vs. solitary or few in terminal racemes).

Description:—Herbs perennial, 3–6(–50) cm tall, glabrescent. Leaves usually basal, rosette, simple, undivided; petiole 1–4.5(–9) cm; blade papery, ovate-elliptic to suborbicular, 4–8(–15) × 3–6(–10) cm, base and apex subrounded, margin subentire or shallowly serrate; lateral veins 7–9 on each side of midrib. Flowers solitary or 3–7 flowers in clusters. Pedicel ca. 6.5–16.5 cm. Bracts borne at the base of pedicel, lanceolate or broadly lanceolate, 5–9 × 1–2 mm, glabrous. Calyx campanulate, 2–3.5 cm; teeth long triangular, 0.4–1 cm × 1.5–5 mm, apex acute. Corolla red, 4.5–7 × ca. 4 cm; tube 4.5–5 cm, purple-red striate and spotted in the inner surface; lobes suborbicular, 1.5–1.9 × 2–2.5 cm. Stamens 4, dydinamous, inserted at base of corolla tube; filaments glandular-hairy 4; the longer pair 2 mm, the shorter pair 1.8 mm. Style 5–6 cm, stigma flabellate. Capsule lanceolate, compressed, 4-angled, 5–7 cm × 7–9 mm, apex acuminate. Seeds subspherical, 3.5–4.5 × 3–4 mm, wing 0.5–0.8 mm wide.

Etymology:—The specific epithet ‘ uniflora ’ refers to the growth pattern of flowers, solitary or clustered.

Distribution, Habitat, and Phenology:— Incarvillea uniflora is distributed in Hengduan Mountains (Markam County, Xizang, China). It grows in natural grassland at an elevation of 4061 m. The flowering period is from May to July and the fruiting period is from July to September.

Preliminary conservation status:—The observation of the field population indicated that Incarvillea uniflora had a narrow distribution range, but its habitat, natural grassland, was very common in Hengduan Mountains. Furthermore, considering the Incarvillea species were widely distributed in Hengduan Mountain, we speculated that there could exist potential undiscovered populations. Therefore, it should be classified as Data Deficient (DD) based on the International Union for Conservation of Nature Red List criteria ( IUCN 2012).

Additional specimens examined (Paratypes):— CHINA. Xizang: Markam , Nov. 2014, X. Z . Lan , L . Q . Li & J .

Luo 542129140618419LY (IBSC, SWCTU).

Additional specimens of related species examined:— I. forrestii : CHINA. Yunnan, Singri-La, Jul. 1914, G . Forrest 12676 ( E); Singri-La, Jul. 1922, G . Forrest 21526 ( E); Sichuan, Muli ,, G . Forrest 30633 ( E) ; CHINA. Sichuan: Ningnan, May 1978, Ningnan team 0093 ( SM). I. mairei : CHINA. Yunnan, Sep. 1929, R . C . Qin 24368 ( PE, KUN). I. altissim : CHINA. Sichuan: Xinlong , June 1974, J . F . Wang 06393 ( CDBI). I. himalayensis : BHUTAN. Chojo Dzong , July 1949, F . Ludlow , G . Sherriff & J . H . Hicks 16722 ( E) .

Figures

FIGURE 1. Incarvillea uniflora. A. plant; B. flower anatomy; C. style and anthers; D. capsule; E. seed. Drawn by A. K. Tang based on the holotype of I. uniflora.

FIGURE 2. Incarvillea uniflora. A. Plants; B. habitat; C. flower, front view; D. flower anatomy; E. capsules.

FIGURE 3. Microstructure of Incarvillea uniflora. A. style and anthers; B. enlarged anther showing glandular hairs; C. seed.