Zingiber oligophyllum K.Schum., 1904

Bai, Lin, Leong-Škorničková, Jana, Xia, Nian-He & Ye, Yu-Shi, 2016, Taxonomic studies on Zingiber (Zingiberaceae) in China III: Z. ventricosum, a new species from Yunnan, and notes on three closely related species, Phytotaxa 261 (2), pp. 101-120 : 107-111

Zingiber oligophyllum K.Schum. in Engler, Pflanzenr. IV. 46 (Heft 20): 185. 1904. ( Figs. 4B , 5–6 )

Lectotype (designated here):— CHINA. Taiwan : Bank-wung-Bergen, [spelled as Bangkinseng on the type specimens, Taiwan, Pingtung Xian, Wanluan Xiang, Wanjin Cun], A. Henry 1605. ( K! [barcode K000815678 ]; isolectotype US! [barcode 00092878]). Remaining syntype: ibidem, A.Henry 1605 A ( K! [barcode K000815679 ])

[ Z. mioga auct. non (Thunb.) Roscoe: Wu & Chen in Wu (Ed.), Fl. Reipubl. Popularis Sin. 16: 146. 1981, quoad syn. Z. oligophyllum K.Schum. ; Wu & Larsen in Wu & Raven (Eds.), Fl. China. 24: 332. 2000, quoad syn. Z. oligophyllum K.Schum. ]

Perennial rhizomatous herb 0.8–1.5 m tall. Rhizome s fleshy, compacted, densely branched, 1.5–2 cm in diam., light brown externally, brownish yellow internally; root tubers ovate, formed distanced from the rhizomes, ca. 2.7 × 1.4 cm, pale brown externally, cream-white internally. Leafy shoots 1–8 per plant, forming dense clumps, spreading, each shoot comprising 8–15 well-developed leaves at flowering, basal 1/3 to 1/2 leafless; leaf sheaths green, sparsely white pubescent; ligules reduced, 1–2 mm long, weakly bilobed, membranaceous when young, turning scarious with age, pale green, slightly pubescent; petiole up to 3.5 cm long, comprising a pulvinus and the narrowed base of lamina, in some old individuals consisting of pulvinus only, pulvinus 1–5 mm long, slightly pubescent; lamina narrowly obovate, sometimes narrowly ovate on young plants, 19–42 × 7–10.5 cm, length:width ratio 2.5–3.5, prominently plicate, adaxially green, sparsely pubescent, abaxially pale green, densely appressed pubescent, base auriculate or attenuate, apex acuminate. Inflorescences 1–4 per plant, radical; peduncles procumbent, 7–16 cm long, ca. 0.6 cm in diam., glabrous, sheathing bracts narrowly ovate, 8–35 mm long (shortest at basal ones, progressively longer distally), ca. 2 cm wide when flattened, green with pink-red tinge at base, with prominent ridges abaxially; spike narrowly ovoid to fusiform-ovoid, 7–11 × 3.5–4 cm, comprising 11–21 bracts, each subtending single flower (uppermost 2–3 bracts usually sterile); fertile bracts loosely arranged, often leaving the rachis exposed at flowering, narrowly ovate, ca. 4 × 1.4 cm, yellowish green, usually red tinged at base and apex, turning red with age, glabrous externally and internally, usually slightly involute on both sides, apex acute to attenuate; bracteole narrowly ovate, ca. 35 × 18 mm (width when flattened), semi-translucent green with slight red tinge towards the base, glabrous externally and internally, apex acute. Flowers 5–6.2 cm long, much exserted beyond the bracts; calyx tubular, membranaceous, ca. 11 mm long, with unilateral incision ca. 5 mm deep, semi-translucent, glabrous externally and internally, apex obtuse; floral tube ca. 4 cm long, cylindrical at base (ca. 2.5 mm in diam.) to weakly funnel shaped at apex (ca. 3 mm in diam.) wide at apex, cream-white, glabrous externally and internally; dorsal corolla lobe narrowly ovate, ca. 25 × 7 mm, pale yellow, glabrous externally and internally, apex mucronate; lateral corolla lobes narrowly ovate, ca. 24 × 4 mm, pale yellow, glabrous externally and internally, much deflexed; labellum narrowly ovate, ca. 20 × 4 mm when flattened, thin and yellow on the margin, thicker and pale yellow in the middle, glabrous, apex emarginated, incised or entire, margins slightly undulate and revolute; lateral staminodes narrowly oblong to spathulate, 11–14 × 2–3.5 mm when flattened, connate to labellum at ca. basal 1/3, pale yellow to yellow, glabrous, apices rounded. Stamen ca. 17 mm long (ca. 19 mm long with anther crest stretched); filament ca. 2 mm long, 2.5 mm wide, cream-yellow, glabrous; anther ca. 9 mm long (excluding anther crest), connective tissue yellow; anther thecae two, 9 mm long, dehiscing throughout entire length, pollen light yellow; anther crest beak-shaped, ca. 6 mm long when stretched, bright yellow, apex entire. Style filiform, white, glabrous; stigma extending to the end of anther crest, slightly thicker than the style, ca. 2 mm long, funnel-shaped, white, ostiole ciliate. Ovary cylindrical, trilocular, ca. 7 × 5 mm, cream-white, glabrous; epigynous glands two, narrowly conical, ca. 5 mm long, 0.3 mm in diam. at base, pale yellow, apices sharp. Fruits not seen.

Typification:—In the protologue Schumann (1904) cited two collections, A.Henry 1605 and A.Henry 1605A, without nominating a holotype. Yeh et al. (2013) incorrectly labelled an image of A.Henry 1605A as holotype, without acknowledging the existence of at least two syntypes. Since this citation did not include “designated here” or any equivalent phrase (fide ICN Art. 7.10, see McNeill et al. 2012), it does not constitute an “unintended” lectotypification (Art. 9.9, Note 6) ( McNeill et al. 2012) where lectotypification would be accepted with the misused term to be corrected. Although both Henry’s collections represent the same taxon it cannot be ascertained if they are part of a single gathering and are therefore treated as syntypes. It is necessary to select a lectotype from among the three existing syntype specimens, namely, A.Henry 1605 (two sheets, K 1×, US 1×) and A.Henry 1605A (K). We have therefore selected A.Henry 1605 (K) as the lectotype, because it has the best-preserved mature inflorescence and leafy shoot, and has been annotated as Z. oligophyllum by Schumann.

Distribution and provisional IUCN conservation assessment:— Zingiber oligophyllum occurs in mainland China (Fujian and Guangdong Provinces), Hong Kong and Taiwan. Further discussion of the distribution of this species is provided in the notes below. In previous works ( Wang et al. 2012, Yeh et al. 2013), Z. oligophyllum was reported as occurring only in Taiwan and was therefore treated as Endangered. However, our studies show this species to be far more widely distributed with an extent of Occurrence (EOO) of about 97,000 km 2. It is therefore here proposed as globally Least Concern (LC) according to the IUCN criteria ( IUCN 2012, IUCN Standards and Petitions Subcommittee 2014). It is possible, however, that with a better understanding of AOO and populations sizes Z. oligophyllum , which is currently from only nine localities (see Fig. 7 ), may need to be reassessed as Vulnerable. In two of its currently known locations this species forms rather small populations with less than 100 individuals (i.e. in Fujian Province it occurs in a forest reserve but within an area subject to high visitor impact, while in Guangdong Province it occurs in a more remote, but unprotected, area).

Ecology and phenology:—In Taiwan, Z. oligophyllum grows in shaded, moist undergrowth of disturbed secondary forest (fruit trees and bamboo mixed forest), at elevation 200– 400 m. In Fujian Province, it grows in lowland areas in moist sandy soil in undergrowth of primary broad-leaved evergreen subtropical rainforest. Flowering commences in mid-August and probably extends until about mid-October. The fruiting has not been observed, but likely extends to December.

Additional specimens examined:— CHINA. Fujian Province: Zhangzhou City, Nanjing Xian, Hexi Zheng , Paradise Tropical Rain Forest Reserve , elev. 600 m, 18 September 1999, Y. F. Deng & L. X.Zhou 13635 ( IBSC) ; ibidem, 15 August 2014, L. Bai & Q. M. Qin 14081501 ( IBSC) . Guangdong Province: Yingde City, forest on roadside of Road 378, 6 July 2014, Y. F. Deng et al. 25582 ( IBSC) ; Jiangmen City, Taishan Xian, Dalongdong , 2 August 1930, J. L. Zuo 22470 ( IBSC). Shenzhen city (photo record) . Hong Kong: New Territories, Saigon , K. Y. Tam s.n. ( HK) . Taiwan: Pingtung Xian, Majia Xiang, Litingshan , 24 September 1993, T. C. Huang 16142 ( TAI, 2×) ; ibidem, 5 September 2006, C. I. Huang 2851 ( HAST) ; Jiayi Xian, Yunshuixi , 14 September 1917, Y. Shimada s.n. ( TAI) .

Notes:— Zingiber oligophyllum was described by Schumann (1904) based on two collections from Pingtung Xian in Taiwan. This name has been treated as a synonym of Z. mioga (Thunb. in Murray 1784: 51) Roscoe (1807: 348) and in several Chinese floristic works such as Flora Reipublicae Popularis Sinicae ( Wu & Chen 1981), Flora of China ( Wu & Larsen 2000) and Flora of Yunnan ( Tong 1997). Although Z. oligophyllum was overlooked in the first edition of the Flora of Taiwan ( Moo 1978), it was included as a distinct species in the second edition of that work ( Wang 2000). Zingiber oligophyllum and Z. mioga are clearly different species and are not particularly closely related, despite the fact that Schumann (1904) compared them in the protologue of Z. oligophyllum . Zingiber mioga is readily distinguished by its longer ligules (ca. 4 mm), much shorter petioles (less than 2 mm), densely imbricate bracts (spike rachis completely covered by bracts) and narrowly oblong laminas (24–26 × 3–4 cm with average length: width ratio 6–8), compared to much reduced ligules (1–2 mm long), long petioles (to 3.5 cm long), loosely arranged bracts (spike rachis often exposed) and narrowly ovate to narrowly obovate laminas (26–28 × 8–10 cm, average length: width ratio 2.5–3.5) in Z. oligophyllum .

Zingiber oligophyllum had long been thought to be endemic to Taiwan, known only from its type locality. However, Yeh et al. (2013) reported new occurrences from Gaoxiong City and Nantou City, extending the geographic range of the species from southern to central Taiwan ( Fig. 7 ).

In 2012 a herbarium collection from mainland China, Fujian Province (Y.F.Deng & L.X.Zhou 13635) was tentatively identified by us as Z. oligophyllum because it possessed reduced ligules, much-elongated petioles and loosely arranged bracts. To check if the floral details of this collection matched those of Z. oligophyllum from Taiwan, the first author visited the Fujian collection locality in 2014, and successfully gathered flowering material. Following comparison with the protologue and type specimens of Z. oligophyllum , and with pictures given in Yeh et al. (2013), it was confirmed that the Fujian Province collections did indeed belong to Z. oligophyllum . In addition, two collections from northwestern and southern Guangdong Province, a collection from Hong Kong and a photographic record from Shenzhen City, Guangdong Province on the Chinese Herbarium Website ( CFH 2016) , have also been identified by us as Z. oligophyllum . This further extends the distribution of Z. oligophyllum within mainland China (see Fig. 7 ).

The above description and the colour plates given in Figs 5–6 are based on the 2014 collection from Fujian Province.

Figures

FIGURE 4. Type specimens of the four species in “Zingiber oligophyllum” complex. A. Z. ventricosum (holotype, L.Bai 14082601, IBSC). B. Z. oligophyllum (lectotype, A.Henry 1605, K). C. Z. thorelii (lectotype, C.Thorel 2363, P) D. Z. xishuangbannaense (lectotype, S.Q.Tong 24808, HITBC).

FIGURE 5. Zingiber oligophyllum K. Schum. A. Habit (inset: young spike). B. Leaf sheaths and ligules. C–D Young shoots (note the presence of petioles in C). E. Rhizomes with radical inflorescences. F. Cross-section of rhizome. Based on L.Bai & Q.M.Qin 14081501. Photos: Lin Bai.

FIGURE 6. Zingiber oligophyllum K. Schum. A. Inflorescence with a flower. B. Flower (front view). C. Single flower (side view; bracteole removed). D. Dissection (from left): bract, bracteole, calyx, dorsal corolla lobe, two lateral corolla lobes, labellum with lateral staminodes basally connate (abaxial view), apical part of floral tube with stamen and style, ovary with two epigynous glands. Based on L.Bai & Q.M.Qin 14081501. Photos: Lin Bai.

FIGURE 7. Distribution of Zingiber oligophyllum (purple), Z. thorelii (yellow), Z. ventricosum (red), and Z. xishuangbannaense (blue). Type localities of the four species are marked with stars. Distribution records are based on study of herbarium material, living material and photographic records.