Zingiber tenuifolium L. Bai, Škorničk. & N.H. Xia, 2015
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publication ID |
https://doi.org/ 10.11646/phytotaxa.227.1.10 |
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persistent identifier |
https://treatment.plazi.org/id/4F5D312A-BD27-0A37-F2EF-19AA8A1FFF43 |
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treatment provided by |
Felipe |
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scientific name |
Zingiber tenuifolium L. Bai, Škorničk. & N.H. Xia |
| status |
sp. nov. |
Zingiber tenuifolium L. Bai, Škorničk. & N.H. Xia View in CoL , sp. nov. ( Figs. 1–3 View FIGURE 1 View FIGURE 2 View FIGURE 3 )
Similar to Zingiber shuanglongense in loosely arranged bracts, violet labellum and lateral staminodes, and short ligules, but differs by leafy shoots composed of 13–23 leaves, smooth, linear to narrowly ovate laminae, 18–23 × 1.5–3 cm (average length: width ratio ca. 10), and floral tube extending only 2 mm beyond the bract (compared to leafy shoots with 5–12 leaves, weakly plicate, oblong or ovate laminae, 12–20 × 3–6 cm (average length: width ratio ca. 4), and floral tube extending at least 15 mm beyond the bract in Z. shuanglongense ).
Type:— CHINA. Yunnan Province: Xinping Xian, Pingdian Xiang, Qingrengu scenic spot, elevation 500–700 m, 27 August 2013, L. Bai 13082701 (holotype IBSC (inclusive inflorescences preserved in alcohol in a jar); isotypes E, KUN, SING, US).
Perennial rhizomatous herb 0.8–1.2 m tall. Rhizomes fleshy, tuberous, branched, 1–1.6 cm in diam., light brown externally, yellow to greenish-yellow internally; root tubers bluntly fusiform, white externally and internally. Leafy shoots 3–5 per rhizome, spreading to weakly arching, with 13 to 23 well-developed leaves when flowering, basal 1/5 leafless; pseudostem ca. 1 cm in diam. at base, ca. 6 mm in diam. in the middle; leaf sheaths sparsely pubescent, lower sheaths pink at base, purple red in the middle, green on upper part, upper sheaths green throughout; ligules to 2 mm long, hyaline membranous, glabrous, weakly bilobed, apices round; petiole 1–5 mm long (longer on the leaves in the middle of the shoot), consisting of pulvinus only, densely appressed-pubescent; lamina thin, linear to narrowly ovate, 18–23 × 1.5–3 cm (average length: width ratio ca. 10), adaxially mid to dark green, smooth (not plicate), glabrous, abaxially pale green, sparsely pubescent, hairs silvery, appressed, base attenuate to obtuse, apex caudate, midrib abaxially with 1–1.5 mm wide dark bands along both sides (visible in dry material only). Inflorescences usually 2–3, arising from the rhizome close to the base of the pseudostem; peduncle variable in length, 1–20 cm long, procumbent; sheathing bracts ovate to narrowly ovate, 11–35 × 10–13 mm (shortest at base, progressively longer distally), white with reddish brown tinge at apices, apices mucronate, sparsely pubescent; spikes narrowly ovoid, ca. 6 × 2.4 cm, composed of ca. 18 loosely arranged bracts (2–3 basal bracts usually sterile); sterile bracts narrowly ovate, 40–45 × 12–16 mm; fertile bracts linear to narrowly ovate, 37–51 × 8–10 mm, margins involute, lower part reddish brown, upper part purplish green, glabrous, apex acute, each bract subtending single flower; bracteole narrowly oblong, rolling into a tube, usually one bracteole per flower, rarely two bracteoles observed facing oppositely on both sides of single flower (one of the bracteoles visibly smaller), 28–34 × 9–11 mm when flattened, reddish brown with purple-green tinge at apex, densely appressed pubescent externally, glabrous internally, apex slightly emarginate. Flower 4.8–6 cm long, slightly exserted from the bracts; calyx tubular with unilateral incision to ca. 3 mm, membranous, ca. 1 cm long, semi-translucent white, basally with slightly pink tinge, densely pubescent, apex nearly truncate with no obvious teeth; floral tube ca. 3 cm long, cylindrical to weakly funnel-shaped at apex, 2–2.5 mm in diam., white with slight pink tinge towards apical part, sparsely pubescent externally, glabrous internally; dorsal corolla lobe narrowly triangular-ovate, 25–26 × 7–8 mm, reddish brown, concave, glabrous externally and internally, apex mucronate; lateral corolla lobes narrowly ovate, 23–25 × 4 mm, reddish brown, usually deflexed, glabrous externally and internally; labellum sub-rhombic to ovate, 24–28 × 13–17 mm, deep violet with cream-white patch at base, margin crisped, apex acuminate, obtuse or shortly incised; lateral staminodes narrowly ovate to obovate with acute or obtuse apex, ca. 13–18 × 3–5.5 mm, connate to labellum at basal 1/3 to 1/2, deep violet with cream-white patch at base. Stamen ca. 16 mm long (ca. 25 mm long with anther crest stretched), filament 0.5–1 × 2 mm, cream-white, glabrous; anther 8–10 mm long (excluding anther crest), connective tissue cream white to pale yellow, glabrous; anther thecae 8–10 mm long, dehiscing throughout entire length, pollen creamy yellow; anther crest 10–12 mm long (stretched), reddish brown to deep violet, glabrous, apex bifid or entire. Style filiform, white, glabrous; stigma extends to the tip of the anther crest, slightly thicker than style, 1–1.5 mm long, funnel-shaped, white, ostiole ciliate, mucous inside. Ovary cylindrical, pale greenish-white, 4–6 × 3 mm, densely puberulous, trilocular; epigynous glands two, ca. 3 mm long, narrowly conical, yellowish white, apex sharp. Fruits not observed.
Etymology:— The specific epithet refers to the extremely narrow leaves.
Distribution and preliminary IUCN assessment:— Zingiber tenuifolium is abundant at the type locality, where more than 100 individuals in an area of ca. 2500 m 2 were observed. Another collection was made about 20 km away from the type locality by Mr. Xueyuan Yang, a local herbalist. According to him, it is also seen in Mopanshan National Forest Park, but no herbarium record so far exists to confirm this. No specimen of this species was encountered in major herbaria in China: CDBI, EMA, GXMG, GXMI, HGAS, HITBC, IBK, IBSC, KUN, PE, and SYS. Currently the known extent of occurrence (EOO) of this species is about 288 km 2. Of the two known localities, one is located in a public park and the other is a scenic spot under development, both are influenced by considerable number of visitors. Also, the species is locally harvested from wild as local medicinal plant. At present, we propose to treat this species under ‘Endangered’ (EN) category (B1ab (iv)) according to the IUCN (2012) guidelines.
Ecology and phenology:— Zingiber tenuifolium grows on sandstone and shale-derived substrates, in medium to deep shaded areas in valleys in lowland evergreen broad-leaved forest, usually along the stream. Flowering starts in late August and lasts till early October. According to the local herbalist, first fruiting occurs in September and likely extends to December.
Vernacular names & uses:— Xiao Ye Jiang (ṬḆả, literally translated as ‘small wild ginger’). Local herbalists use the rhizome of this species as well as several other species of Zingiber sect. Cryptanthium , e.g. Z. liangshanense Z.Y. Zhu (1987: 33) , Z. yunnanense S.Q. Tong & X.Z. Liu (1991: 27) , to treat gastritis.
Other specimens examined (paratypes):— CHINA. Yunnan Province: Xinping Xian, Pingdian Xiang, Qingrengu scenic spot, 3 September 2014, L. Bai, 14090301 ( IBSC) ; Xinping Xian, Yangwu Zhen, Dakaimen Cun , 25 Aug 2013, Xueyuan Yang 2301 ( IBSC) .
Notes:— Zingiber tenuifolium is easily recognized from other species in the sect. Cryptanthium in China by narrowly ovate lamina (26–30 × 2–2.5 cm; average length: width ratio ca. 10). The only other species with similarly narrow lamina is Z. lingyunense (average length: width ratio ca. 8), a lime-stone species in Guangxi province, which also have a narrow darker band along both sides of the mid rib on the back of lamina (visible in dry specimens only), slim peduncles and loosely arranged narrow ovate to linear bracts. However Z. lingyunense has a rhizome dark violet internally, weakly plicate lamina, flowers well exserted from bracts, cream-coloured throughout and lateral staminodes connate to labellum at basal 2/3 to 3/4 (compared to yellow to yellowish green rhizome, smooth lamina, flower reddish to violet, floral tube as long as the bract, and lateral staminodes connate to labellum at basal 1/3 to 1/ 2 in Z. tenuifolium ).
The general shape and colour of the inflorescence and flower of Zingiber tenuifolium is most similar to Z. shuanglongense , a recently described species endemic to Taiwan. The comparison to this species has been already given in the diagnosis. Zingiber shuanglongense was originally published with a grammatically incorrect Latin termination as Zingiber shuanglongensis . Following Arts 23.5 and 32.2 of the ICN (McNeill et al. 2012), this is corrected here to ‘ shuanglongense ’.
Zingiber tenuifolium is also somewhat similar to Z. kawagoii from Taiwan in general colour of the flower and shape of bracts, but Z. kawagoii only have 12–17 leaves, the laminae are plicate, oblong or ovate, (average length: width ratio only ca. 3.3), the floral tube is yellowish and the lateral staminodes connate to labellum at basal 2/3 to 3/ 4 in Z. kawagoii (compared 13–23 leaves, smooth linear or narrowly ovate laminae, with average length: width ratio ca. 10, floral tube white with slight pink tinge and the lateral staminodes connate to labellum at basal 1/3 to 1/ 2 in Z. tenuifolium ).
A thorough comparison of the four species is given in Table 1.
on Hayata 1921 and Wang 2000), Z. lingyunense (based on Fang 1980) and living collections from type locality, L.Bai
12081634).
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