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.

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!).

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.

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).

Flowering from March to April.

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

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

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.

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).

Henckelia multinervia is similar to H. ceratoscyphus (B.L. Burtt) D.J. Middleton & Mich. Möller in the shape, color and size of the flower, the indumentum of leaf blade and the horn-like calyx apex, but it can easily be distinguished from the latter by the shape of leaf blade and distinct venation pattern, smaller horn-like calyx apex, the indumentum of corolla and style and smaller stigma.

China. Yunnan: Hekou County, Laofanzhai Town, Jinzhuliang village, Shiqiao, 22°47'N, 103°49'E, 442 m a.s.l., on moist rocks in rainforest valley along the bank of the stream, in flower, 3 Apr 2018, G.L. Zhang CL2018008 (holotype: KUN!, isotypes: KUN!).

Figure 3. 

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

Figure 4. 

Holotype of Henckelia multinervia Lei Cai & Z.L.Dao (KUN-1443559).

Perennial, stem extremely short, usually less than 1 cm. Rhizome 0.8–5.0 cm long, internodes inconspicuous. Leaves basal, opposite; petiole 2–16 cm long, ca. 1 mm in diameter, densely pubescent; leaf blade long-elliptic to broadly lanceolate, 4–34 × 2–8 cm, herbaceous, adaxially densely puberulent, eglandular, abaxially puberulent and densely puberulent along veins, base oblique, cuneate on both sides, margin serrate, apex acute; lateral veins 12–22 on each side of midrib, conspicuous on both sides. Cymes 2–5 per plant, each 1–3-flowered; peduncle 1.2–2.5 cm long, pubescent; bracts 2, free, lanceolate, ca. 8–10 × 3–5 mm, pubescent both sides, margin entire, apex acute. Pedicel 1.5–2.5 cm long, pubescent. Calyx 1.2–2.0 cm long, 5-divided to near base; lobes equal, lanceolate to oblong, 1.2–2.0 cm long, outside pubescent, inside glabrous, apex attenuate, horn-like, 4–6 mm long. Corolla blue-purple, with two yellow stripes and several purple stripes on the abaxial lip, 3.5–5.0 cm long, outside glandular pubescent, inside glabrous; tube funnelform, outside white, ca. 2.8–4.0 × 0.2–1.5 cm; adaxial lobes 2, orbicular, ca. 1.5 cm in diameter; abaxial lobes 3, orbicular, ca. 1.8 cm in diameter. Stamens 2, anthers adaxially fused, ca. 2 mm long, puberulent; filaments 6–8 mm long, inserted ca. 1.2 cm from base, glabrous below, sparsely glandular puberulent apically; staminodes 3, central one ca. 1.5 mm long, laterals ca. 4 mm long, inserted ca. 1.3 cm from base. Disc ca. 1 mm high, shallowly 5-lobed. Pistil 2.4–2.8 cm long; ovary long elliptic, 8–10 mm long, densely pubescent; style linear, 1.5–1.8 cm long, glandular puberulent; stigma flabellate, ca. 2 mm long, 2-lobed. Old capsule (from the previous year) ca. 3.2 cm long.

Flowering from March to April; fruiting from April to May.

The specific epithet ‘multinervia’ is Latin, and refers to the relatively large number veins of this species.

The Chinese mandarin “duo mai han ke ju tai” (多脉汉克苣苔)

This species is currently known only from the type locality, where ca. 80 individuals were found on moist rocks beside a river in a rainforest valley. More field work is required to assess the conservation status.

China. Yunnan: Hekou Couty, Laofanzhai Town, Jinzhuliang village, Shiqiao, 22°47'N, 103°49'E, 442 m a.s.l., on moist rocks in rainforest valleys along stream, in flower, 11 Apr 2018, Lei Cai et al. CL084 (KUN!); Hekou County, Laofanzhai Town, Jinzhuliang village, Shenchong, 22°47'N, 103°49'E, 485 m a.s.l., on moist rocks in the rainforest valley along streamsides, in flower, 8 Mar 2017, G.L. Zhang ZhangGL222 (KUN!).

The new species is most similar to H. ceratoscyphus in its habitat and floral characteristics, but can easily be distinguished from the latter by having long-elliptic to broadly lanceolate leaf blade (vs. narrowly to broadly elliptic); more lateral veins up to 12–22 pairs (vs. 7–11 pairs); the horn-like apex up to 1/4–1/3 of the length of calyx (vs. 1/2–2/3 of the length of calyx); the corolla glandular pubescent outside (vs. sparsely puberulent outside), the glandular pubescent style (vs. puberulent); and the ca. 2 mm long stigma (vs. ca. 6 mm long).