 |
| Zingiber chengii Y.H.Tseng, C.M.Wang & Y.C.Lin
in Wang, Lin & Tseng, 2020.
|
Abstract
In this article, we describe a new species, Zingiber chengii Y.H. Tseng, C.M. Wang & Y.C. Lin, discovered on a rock cliff of Youluo riverside in northern Taiwan. This species is easily distinguished from other known congeners by its grass-like leaves, spikes composed of a few sterile bracts, and seeds one-third enveloped by the aril. Color illustrations, line drawings, and a key to species of Zingiber in Taiwan are provided as well as comparative morphology in relation to its allied species, geographical distribution, and conservation status.
Keywords: northern Taiwan, riverside, rock cliff, Zingiber
 |
| Figure 1. Line drawings of Zingiber chengii Y.H.Tseng, C.M.Wang & Y.C.Lin, sp. nov. A habit B base of plant C rhizome D−E leaf adaxial and abaxial surface F ligulate G−K bracts and bracteoles L dorsal corolla lobe M lateral corolla lobe N−O inflorescences P flower Q pistil R stamen and anther crest S labellum with basally connate lateral staminodes T fruit. |
 |
| Figure 2. Phenologic phases of Zingiber chengii Y.H.Tseng, C.M.Wang & Y.C.Lin, sp. nov. A withering period B dormant period (rhizome) C growth period D mature period E flowering period. |
 |
| Figure 3. Zingiber chengii Y.H.Tseng, C.M.Wang & Y.C.Lin, sp. nov. A habit B rhizome C the cross-section of rhizome D leaf blade E ligule and sheath (side view) E’ sheath (front view) F inflorescence G flower dissection 1 fertile bracts 2 Bracteole 3 calyx 4 dorsal corolla lobe 5 lateral corolla lobes 6 Labellum with basally connate lateral staminodes 7 ovary 8 floral tube with stamen and stigma (side view) H−J fruit K seeds. |
Zingiber chengii Y.H.Tseng, C.M.Wang, & Y.C.Lin, sp. nov.
Diagnosis: Zingiber chengii sp. nov. is morphologically similar to its Taiwanese congeners. However, the new species can be distinguished from them by its deciduous leafy shoots while those of Z. kawagoii, Z. oligophyllum and Z. shuanglongense are evergreen; Z. chengii has narrow lanceolate to linear leaves, whereas Z. kawagoi and Z. shuanglongense have ovate to lanceolate ones; except Z. oligophyllum, which has yellow flowers, all native species of Taiwan have reddish-purple flowers; each spike of Z. chengii bears 1−3 flowers, whereas spikes of Z. kawagoi and Z. shuanglongense bear 8−11 and 4−10 flowers, respectively; Zingiber chengii rarely has sterile bracts, whereas Z. kawagoii and Z. shuanglongense have apparent sterile bracts; Zingiber chengii has ovoid fruit, whereas Z. kawagoii and Z. shuanglongense has ellipsoidal one. Both Z. kawagoii and Z. shuanglongense are almost enveloped by the aril, whereas Z. chengii is one-third enveloped by the aril (Table 1).
Distribution and habitat: Endemic species of Taiwan. Based on the geographical climatic regions and vegetation zones (Su 1984, 1985), Z. chengii is distributed only in the northwest inland region, moist areas of cloud forests of the Machilus–Castanopsis forest zone at an altitude of 530 m, and is found only on the rock cliff of Yuluo riverside (Hsinchu County) in northern Taiwan (Fig. 4). Common companion species are Arundo formosana Hack. (Poaceae), Sedum actinocarpum Yamam. (Crassulaceae), Rhaphidophora hongkongensis Schott (Araceae), Pothos chinensis (Raf.) Merr. (Araceae), Pilea plataniflora C.H.Wright (Urticaceae), and Pyrrosia lingua (Thunb.) Farw. (Polypodiaceae). Sometimes, Z. kawagoii is found nearby; however, no potential hybrid individual has been observed.
Chinese name: Hsia-yeh-chiang (狹葉薑).
Etymology: The species epithet “chengii” was given in honor of Mr. Yuen-Chun Cheng (鄭元春) who first discovered the new species.
Chiu-Mei Wang, Yuan-Chien Lin and Yen-Hsueh Tseng. 2020. Zingiber chengii (Zingiberaceae), A New Species from Taiwan. PhytoKeys. 139: 1-11. DOI: 10.3897/phytokeys.139.37294
