Henckelia nanxiheensis Lei Cai & Z.L.Dao, 2019

Cai, Lei, Liu, De-Tuan, Zhang, Pin & Dao, Zhi-Ling, 2019, Two new species of Henckelia (Gesneriaceae) from Southeastern Yunnan, China, PhytoKeys 130, pp. 151-160 : 151

Henckelia nanxiheensis Lei Cai & Z.L.Dao sp. nov. Figures 1 , 2

Diagnosis.

Henckelia nanxiheensis is morphologically similar to H. auriculata (J.M. Li & S.X. Zhu) D.J. Middleton & Mich. Möller in the shape, color and size of the flower; it also resembles H. ceratoscyphus (B.L. Burtt) D.J. Middleton & Mich. Möller in the indumentum characteristics of the whole plant and hornlike apex of the calyx, but differs from them both in the shape of leaf blade, calyx lobes, size of corolla, indumentum of pedicel and pistil.

Type.

China. Yunnan: Pingbian County, Baiheqiao Town, Dujiao, 22°55'N, 103°51'E, 255 m a.s.l., on the surface of rocks in the shaded valleys, in flower, 18 Mar 2017, Lei Cai CL035 (holotype: KUN!, isotypes: KUN!).

Description.

Perennial; stem extremely short, usually less than 1 cm. Rhizome 0.5-1.0 cm long, internodes inconspicuous. Leaves basal, opposite; petiole 2-11 cm long, ca. 1 mm in diameter, base 3 mm wide, densely pubescent; leaf blade oblong to oval, 4-20 × 1.5-5.5 cm, herbaceous, adaxially densely puberulent, eglandular, abaxially puberulent and densely along veins, base oblique or asymmetrical, margin serrate, apex acute; lateral veins 5-12 on each side of midrib, conspicuous on both sides. Cymes 3-10 per plant, each 1-4-flowered; peduncle 1-2 cm long, pubescent; bracts 2, free, ovate to oval, ca. 3-5 × 2-3 mm, pubescent both sides, margin entire, apex acute. Pedicel 0.8-2.5 cm long, pubescent. Calyx 8-10 mm long, 5-parted to 3/4 of the length; lobes equal, lanceolate to long-triangular, 6-8 mm long, outside pubescent, inside glabrous, apex attenuate, horn-like 3-5 mm long. Corolla ca. 2 cm long, white to pale blue, with light purple stripes inside, abaxial lips purple, outside sparsely puberulent, inside glabrous; tube slightly curved, narrow at base, ca. 10-13 × 2.0-4.5 mm; adaxial lobes 2, orbicular, ca. 4 mm in diameter; abaxial lobes 3, orbicular, ca. 5 mm in diameter. Stamens 2, anthers adaxially fused, ca. 1.5 mm long, sparsely puberulent; filaments ca. 4.5 mm long, S-shaped, inserted ca. 2.5 mm from the base, glabrous below, extremely sparsely glandular-puberulent apically; staminodes 3, green, ca. 0.5 mm long, inserted ca. 3 mm from base. Disc ca. 0.5 mm high, inconspicuous. Pistil 1.1-1.3 cm long; ovary long-elliptic, 3-4 mm long, densely pubescent; style linear, ca. 8 mm long, glandular puberulent; stigma flabellate, ca. 2 mm long, 2-lobed. Fruit unknown.

Phenology.

Flowering from March to April.

Etymology.

The specific epithet ' nanxiheensis ' refers to the type locality in the regions near the Nanxi River, which is a tributary of the Red River.

Vernacular name.

The Chinese mandarin "nan xi he han ke ju tai" (南溪河汉克苣苔)

Distribution and habitat.

The new species is currently known only from the type locality with a small population of ca. 150 individuals growing on moist rocks of the entrance to the valley near the banana plantation. The population of Henckelia nanxiheensis was first discovered in 2014 (without flowers) by Lei Cai; individuals in blossom were collected in 2017. The disturbance of the population has been observed with ca. 15% loss of the original habitat, due to human activities which are not limited to the expansion of banana plantations. An urgent preservation scheme is required to rescue this species from further disturbances or wipe-out from the type locality.

Notes.

This new species most closely resembles Henckelia auriculata in the shapes of the flower and calyx. However, it differs from the latter in the oblong to oval leaf blade with oblique base and serrate margin (vs. rotund to elliptical with auriculate base and shallowly serrate to coarsely dentate margin); the calyx divided 3/4 of the length of calyx (vs. calyx parted to base); the flower lips white to pale blue adaxially and purple abaxially (vs. entirely white); the ovary densely pubescent and the style glandular puberulent (vs. densely but eglandulate hairy pistil). It is also similar to H. ceratoscyphus in the indumentum characteristics and hornlike apex of the calyx, but differs from having leaf blade oblong to oval (vs. narrowly to broadly elliptic), smaller corolla ca. 2.2 cm long (vs. 4.5 cm long), slightly curved tube (vs. tube funnelform), equal size of 3 staminodes ca. 0.5 mm long (vs. central one ca. 1.5 mm long, laterals ca. 6 mm long); the ovary densely pubescent and the style glandular puberulent (vs. puberulent pistil).

Figures

Figure 1. Henckelia nanxiheensis Lei Cai & Z. L. Dao, sp. nov. A Habitat B plants with flowers C front view of flowers D adaxial leaf surface E adaxial and abaxial leaf surfaces F bracts G side view of flower H pistil, disc and calyx I opened corolla. All photographs by Lei Cai.

Figure 2. Holotype of Henckelia nanxiheensis Lei Cai & Z. L. Dao (KUN- 1443557).