Gentianella macrosperma Ma ex H.F. Cao, J.D. Ya & Q.R. Zhang, 2019

Cao, Hai-Feng, Ya, Ji-Dong, Zhang, Qiao-Rong, Hu, Xiao-Jian, Zhang, Zhi-Rong, Liu, Xin-Hua, Zhang, Yong-Cheng, Zhang, Ai-Ting & Yu, Wen-Bin, 2019, Gentianella macrosperma, a new species of Gentianella (Gentianaceae) from Xinjiang, China, PhytoKeys 130, pp. 59-73 : 61-63

Gentianella macrosperma Ma ex H.F. Cao, J.D. Ya & Q.R. Zhang sp. nov. Figures 2 , 3

Diagnosis.

Resembles G. holosteoides , G. longicarpa , G. sibirica , G. stoliczkae and G. umbellata , but differs from them by having even flower size, corolla white, corolla lobe as long as corolla tube, nectaries located close to the throat of the corolla tube and larger seeds.

Type.

CHINA. Xinjiang: Ili Kazak Autonomous Prefecture, Gongliu County, Ji’ergelang Township, Qiaxi Village, on the mountain ridge in the forest, 1780 m elev., 6 September 1956, Shun-Li Chen Tianyi281 (holotype: PE00029466!; isotype: PE00029453!, PE00029471!).

Description.

Herbs, annual. Roots slender, yellow. Stems 30-40 cm, erect, subquadrangular, glabrous, yellowish-green, 2.0-2.5 mm in diameter; branched from the base in axils of each node, more slender, suberect or slightly ascending. Leaves opposite, basal leaves not rosette and withered at anthesis, petiole conspicuous, 7-10 mm long, leaves oblong-spatulate, 14-17 × 2-6 mm, base tapering into petiole, margin entire, apex rounded, veins 3-5, raised abaxially and slightly sunken adaxially; lower cauline leaves obovate-spatulate or rounded-spatulate, petiole 10-18 mm long, leaf blades with petiole 18-31 × 10-11 mm, both surfaces glabrous, base tapering into conspicuous petiole, margin entire, apex rounded, veins 5-7 raised abaxially and slightly sunken adaxially; middle leaves on primary stem elliptic, ovate-elliptic, 25-38 × 10-15 mm, base rounded or truncate, inconspicuously short or subsessile, both surfaces glabrous, margin entire, apex rounded, veins 5-9, raised abaxially and slightly sunken adaxially; upper stem leaves ovate-elliptic to ovate, 15-25 × 7-12 mm, with terminal two pairs of leaves nearly in whorls, both surfaces glabrous, base rounded, sessile, margin entire, apex acute, veins 3-5, raised abaxially and sunken adaxially; lateral branches leaves smaller, 10-15 × 4-7 mm. Cymes terminal and axillary, 3-4 flowers per leaf axil, terminal inflorescence 8-10 flowers, dense, inflorescence flowering at different times, pedicel variable in length and up to 36 mm. Flowers 4-merous (rarely 5-merous), all flowers almost the same size (terminal corolla as long as or slightly longer than others), rotating arrangement. Calyx 3.5-4.5 mm long, slightly shorter than corolla or as long as corolla, divided almost to the base, calyx tube 0.7-0.8 mm long, membranous, lobes green, distinctly unequal, 2 slightly larger, oblanceolate to linear-oblanceolate, 3.0-3.5 × 0.7-1.0 mm, 2 (-3) slightly smaller, linear, 2.3-3.0 × 0.4-0.5 mm, apex acute or acuminate, margin scabrous, midvein raised abaxially, sinus obtuse. Corolla white, campanulate, 4.0-4.5(5.0) mm long; corolla tube 2.1-2.4 mm long; lobes ovate, with light brown fine longitudinal veins, 2.2-2.5 × 1.5-1.8 mm, apex obtuse and mucronate, margin entire. Nectaries 8(-10), green, oblong, naked and indistinct, two nectaries per corolla lobe located very close to the throat of the corolla tube, ca. 0.2 mm from the top of corolla tube. Stamens inserted at middle of corolla tube, filaments white, linear, 1.1-1.4 mm long, anthers blue, rectangular, 0.2-0.3 mm long; ovary elliptic, ca. 2.0 mm long. Style short, linear, 0.4-0.5 mm long, stigma small, 2-lobed. Gynophore short, 0.2-0.3 mm long. Capsule elliptic, a concavity sometimes present in the centre, 2.5-4.0 mm long, usually with 2-8 seeds each capsule. Seeds brown, glossy, flat-ellipsoid, 1.2-1.6 × 0.5-0.9 mm, seed coat wrinkled-reticulate (smooth when immature).

Phenology.

Flowering and fruiting from June to September.

Distribution and habitat.

G. macrosperma is distributed in Gongliu county and Xinyuan county, west of Xinjiang, China. It grows in thickets on the slope or on the mountain ridge in the forest of Picea schrenkiana Fisch. & Mey. at an elevation of 1729-1780 m.

Etymology.

The specific epithet “macrosperma” refers to the larger seeds of this new species.

Vernacular name.

Chinese mandarin: da zi jia long dan (大籽假龙胆)

Conservation status.

Currently only known from three localities in west of Xinjiang, therefore considered to be Vulnerable (VU D2) ( IUCN 2017).

Additional specimens examined (paratypes).

CHINA. Xinjiang: Ili Kazak Autonomous Prefecture, Xinyuan County, on the road from Xinyuan County to the gold mine, 43°16'06.45"N, 83°17'42.90"E, 1729 m elev., 1 July 2017, J.D. Ya, Q.R. Zhang & X.J. Hu 17CS16327 (KUN1443565!, KUN1443566!, KUN1443554!); Ili Kazak Autonomous Prefecture, Gongliu County, Mohuer Township, Damohe Village, 8 August 1976, Shu-Run Liu s.n. (HIMC0026063!, HIMC0026064!. the sheet 0026064 presents a mixture of Swertia dichotoma Linn. which was labelled as “A” and G. macrosperma labelled as “B”)

Figures

Figure 2. Gentianella macrosperma, sp. nov. A plant B flower, top views C-D show opened corollas, 4 - and 5 - merous, respectively E flower, showing the length of calyx and corolla subequal F calyx. showing 4 - merous G calyx, showing 5 - merous H capsule I seeds. Drawn by R. M. Zhang. H and I from the isotype S. L. Chen Tianyi 281 (PE 00029471), others from the paratype J. D. Ya, Q. R. Zhang & X. J. Hu 17 CS 16327 (KUN 1443565). Scale bars: 2 cm (A); 5 mm (B); 2 mm (C-H); 0.5 mm (I).

Figure 3. Gentianella macrosperma, sp. nov. A plant in nature habitat B flowers and inflorescence C flowers, showing pedicels and upper leaves D-E front view and side view of corolla, showing nectaries located close to the throat of the corolla tube F middle cauline leaf, abaxial view, showing veins G plants specimen (from KUN 1443554) H opened corolla (5 - merous) showing ovary I calyx J seed, front view (left and middle) and side view (right) (from S. L. Chen Tianyi 281 (PE 00029471 )). I, H from the paratype J. D. Ya, Q. R. Zhang & X. J. Hu 17 CS 16327 (KUN 1443565). Scale bars: 5 cm (A, G); 2 cm (B); 2 mm (C-E, I, H); 1 mm (J).