Deinostigma fasciculatum W.H.Chen & Y.M.Shui, 2020

Shui, Yu-Min, Wu, Jian-Yong, Yu, Zhi-Yong, Guo, Shi-Wei, Chen, Li, Wen, Fang & Chen, Wen-Hong, 2020, Deinostigma fasciculatum, a new species of Gesneriaceae in Yunnan, China, PhytoKeys 157, pp. 199-206 : 199

Deinostigma fasciculatum W.H.Chen & Y.M.Shui sp. nov. Figure 2

Type.

China. Yunnan province, Jinping County, Ma-an-di town, 22°58'33"N, 104°50'32"E, 11 August 2018, collected from the living plants at Kunming Botanical Garden, Y.M. Shui & S.W. Guo B2018-493 (holotype, KUN!).

Diagnosis.

The new species is similar to D. cicatricosum and D. cyrtocarpum in dark purple flowers and falcate fruit, but differs from the latter two species in the inflorescences with fasciculate flowers (vs. with remote flowers), calyx lobes reflexed (vs. compacted), corolla tubes white outside and below throat (vs. purple) (Figs 2C , 3 ). The new species differs from D. cicatricosum in calyx lobes narrowly lanceolate (vs. narrowly oblong) and 1.2-1.3 cm long (vs. 0.8-1.0 cm), corolla tube sharply contracted below middle (vs. slightly contracted), capsule narrowly oblong (vs. linear) 2-2.5 cm long (vs. 3-4 cm long). It differs from D. cyrtocarpum in calyx lobes 1.2-1.3 cm long (vs. 0.5-0.8 cm long), corolla tube sharply contracted (vs. gradually contracted).

Herbs perennial.

Stems pendulous, 30-60 cm long, densely glandular villous. Leaves alternate near stem apex; petiole 2-3.5 cm long, densely glandular villous; leaf blade herbaceous, ovate, elliptic or cordate, 3-9 × 2.5-4 cm, base oblique, often slightly peltate, cuneate, cordate or round, apex acuminate, margin serrate, adaxially densely glandular villous, abaxially densely glandular villous; venation penninerved, lateral veins 3-5 on each side of mid-rib. Cymes axillary near stem apex, fasciculate; peduncle 1.5-11.5 cm long, densely glandular villous; bracts 2, ovate, caducous, 0.8-1.2 × ca. 0.6 cm, adaxially sparsely glandular villous, abaxially densely glandular villous; bracteoles 2, lanceolate, caducous, ca. 0.6 × 0.2 cm, adaxially sparsely glandular villous, abaxially densely glandular villous; pedicel ca. 0.5 cm long, densely glandular villous. Calyx 5-parted to the base, segments lanceolate, 1.2-1.3 × ca. 0.2 cm, apex acute, margin entire, outside densely glandular villous, inside sparsely glandular villous. Corolla funnelform, zygomorphic, 3.5-4 cm long, ca. 1 cm wide at the throat, outside dark purple, densely glandular pubescent, inside dark purple, glabrous; tube ca. 2.5 cm long; limb 2-lipped, adaxial lip 2-lobed, lobes semi-circular, ca. 0.8 cm long, 0.5 cm in diam. at base; abaxial lip ca. 1.5 cm long, 3-lobed, middle lobes orbicular, ca. 0.5 × 0.5 cm, lateral lobes orbicular, ca. 0.5 × 0.6 cm. Stamens 2, adnate to corolla tube ca. 1.5 cm from base, coherent; anthers densely villous; filaments densely villous, ca. 1.2 cm long; staminode 3, lateral 2, villous, slightly coherent with the anthers, adnate to corolla tube ca. 1.5 cm from base, ca. 0.8 cm long; middle 1, adnate to corolla tube ca. 1.5 cm from base, ca. 1 mm long. Disc ring-like, ca. 1 mm high. Pistil ca. 3.5 cm long; ovary linear, densely glandular pubescent, ca. 0.8 cm long; style linear, ca. 2.7 cm long; stigmas obtrapeziform, emarginate. Capsule obliquely narrowly oblong, 2-2.5 cm long, curved.

Phenology.

Flowering is from May to August and fruiting from July to September.

Etymology.

The name refers to the flowers, which are fasciculate on inflorescences of the new species.

Vernacular name.

Cù Huā Qí Zhù Jù Tái (Chinese pronunciation); 簇花奇柱苣苔 (Chinese name).

Distribution and habitat.

The new species only grows on the wet cliff in the valley and only occurs at the type locality, Jinping County, Yunnan province, China.

Additional examined specimens.

China. Yunnan province: Jinping county, Ma-an-di town, 22°58'33"N, 104°50'32"E, in valleys, alt. 500 m a.s.l., with fruits, 22 January 2016, Y.M. Shui & W.H. Chen B2016-084 (KUN!). The same county, Ma-an-di town, Maguaitang village, on wet cliff, alt. 520-850 m a.s.l., with buds, 1 May 2019, Z.Y. Yu B2019-001 (KUN!).

Conservation state.

The new species has been only observed from the type locality in the nature reserve, with ca. 30, 000 m2 area (300 m × 100 m) and ca. 160 mature individuals on the cliff. The type locality is located in a deep valley with a small power station. Occasionally, local people go there to camp. Additionally, due to the building of a road, some of the slopes may become unstable and fall, resulting in some individuals being destroyed in the future. So, we hereby assessed the new species as "Critically Endangered (CR)" (C2+a+ii or B2+b+iii). ( IUCN 2012, 2017).

Note.

Deinostigma cyrtocarpum is easily distinguished from D. cicatricosum and D. fasciculatum by its short calyx (Figs 1 , 3J ). Secondly, in D. cicatricosum and D. fasciculatum , corolla tubes are obviously contracted at the middle. As to the L/U ratio (width of lower part/width of upper part of corolla tube), the L/U ratio of D. cicatricosum is about 1/2.5 and lightly contracted, while the L/U ratio of D. fasciculatum is about 1/5 and sharply contracted (Figs 2 , 3 ). Besides, after the careful examination of the type specimens, Deinostigma minutihamatum is distributed in Central Vietnam with 2300 m elevation and characterised by almost straight capsules instead of falcate capsules and so considerably different from the Chinese species of the genus with falcate capsules (Fig. 2B ; Wang et al. 1998, Wei et al. 2010).

Figures

Figure 1. The distribution of Deinostigma fasciculatum W. H. Chen & Y. M. Shui, sp. nov. (■), with D. cicatricosum (W. T. Wang) D. J. Middleton & Mich. Moeller (●) and D. cyrtocarpum (D. Fang & L. Zeng) Mich. Moeller & H. J. Atkins (▲).

Figure 2. Deinostigma fasciculatum W. H. Chen & Y. M. Shui, sp. nov. A habit B mature fruits C frontal view of flower D leaf abaxial side E top and back view of flowers F top view of opened corolla showing the interior surface of corolla tube, stamens and staminodes G pistil and calyx, arrow showing the calyx H ovary, calyx and bract. (b = bract, c = calyx, d = disc).

Figure 3. Photographs of Deinostigma cicatricosum (W. T. Wang) D. J. Middleton & Mich. Moeller (A-H) and D. cyrtocarpum (D. Fang & L. Zeng) Mich. Moeller & H. J. Atkins (I & J) A habit B adaxial surface of leaf C frontal view of flower D top view of flower E opened corolla showing the interior surface of corolla tube, stamens and staminodes, arrows showing the staminodes F stamens and staminodes, arrows showing the staminodes G pistil and calyx H bract and young flower I inflorescence of D. cyrtocarpum J lateral view of inflorescence (b = bract, c = calyx, d = disc).