Amomum xizangense L.Fu, J.P.Huang & Y.S.Ye, 2021

Fu, Lin, Huang, Jian-Ping, Wu, Xing, Du, Zhi-Jian, Lin, Ling & Ye, Yu-Shi, 2021, Amomum xizangense (Zingiberaceae), a new species from Xizang, China, Phytotaxa 525 (3), pp. 232-236 : 232-235

Amomum xizangense L.Fu, J.P.Huang & Y.S.Ye , sp. nov. ( Fig. 1 )

Type: — CHINA. Xizang: Medog County, Beibeng Xiang , at the forest edge, 29°14′30″N, 95°09′32″E, elev. ca. 800 m, 2 July 2013, Yu-Shi Ye 5644 (holotype: IBSC!)

Diagnosis:— Amomum xizangense is similar to A. maximum and A. subcapitatum , but differs in having purple-red leaf sheath, purple-red or reddish-green petiole, lamina with purple-red midvein, persistent bracts and bracteoles, yellowish-white calyx, yellowish corolla, yellow anther with trilobed and yellow anther crest and globose fruit.

Herb 1.5–3 m tall, clump-forming, with 5–20 pseudostems (leafy shoots) per clump. Rhizome 3.5–5.0 cm in diameter, outside green, inside (cross section) white; stilt roots absent; interval between pseudostems 2–10 cm long; scales broadly ovate, initially dark red, brown when old, coriaceous, striate, outer surface densely pubescent, apex acute, margin ciliate. Pseudostem with 5–11 leaves, base slightly swollen, 3.0– 4.5 cm in diameter, becoming slightly smaller towards apex; leaf sheaths purple-red, outer surface striate, shiny, tomentellous, margin membranous; ligule ovate or narrowly ovate, apex bifid, 1–1.8 × 0.8–1.0 cm, light red, old brown, coriaceous, densely pubescent; petiole stout, canaliculate, 2.5–13 × 0.8–1.0 cm, purple-red or reddish green, striate, shiny, pubescent; lamina oblong to elliptic or oblanceolate, 75–130 × 11–22 cm, adaxially green, glabrous, shiny, abaxially densely silvery sericeous, base attenuate, apex acuminate, midvein prominent below, purple-red. Inflorescence arising from base, 2–4 per pseudostem; peduncle 1–6 cm long; scales triangular to broadly ovate, 0.8–2 × 2.5–3.1 cm, initially red, brown when old, striate, tomentellous; spikes ovoid to ellipsoid, 4.0–5.5 × 3–4 cm; sterile bracts ovate, 4–4.5 × 2.8–3.5 cm, initially red, brown when old, coriaceous, outside densely yellow brown tomentellous, margin ciliate, apex cucullate, base narrowed, persistent; fertile bracts each subtending two flowers, ovate or narrowly ovate, papery, 4–4.8 × 1.8–3.1 cm, light red, outside densely white tomentellous, glabrous inside, apex acute, base narrowed, margin ciliolate, persistent; bracteoles oblonglanceolate, usually half-folded, enclosing flowers, thin papery or nearly membranous, 3–3.5 × 1.0– 1.3 cm, rose pink at apex, white at base, with longitudinal stripes, outside densely tomentellous, glabrous inside, apex acute, persistent. Flower 6–7 cm long, yellow; pedicels 0.5–1.0 × 0.2–0.3 cm, pale yellow or light pink, densely pubescent; calyx tubular, 2.5–3.0 × 0.5–0.7 cm, yellowish white, outer surface densely pubescent, 3-toothed, teeth apiculate at apex; floral tube 0.2–2.2 × 0.3–0.5 cm, yellowish white, coriaceous, densely tomentellous; dorsal corolla lobe oblong, 3.0– 3.2 × 0.8–1.0 cm, yellowish, membranous, with translucent longitudinal stripes, outside pubescent, glabrous inside, apex apiculate; lateral corolla lobes narrowly obovate, 2.2–2.6 × 0.5–0.7 cm, yellowish, membranous, with translucent longitudinal stripes, outside pubescent, glabrous inside, apex cucullate; lateral staminodes subulate, 1.5–2.5 × 1.0– 1.5 mm, red at base, yellowish distally, with short glandular hairs, apex acute or 2-lobed; labellum narrowly obovate, 2.2–2.7 × 0.8–1.6 cm, yellow, glabrous, midvein thickened and each side with 1 red stripe, sometimes with sparse red spots, margin crisped; filament flattened, 7.0–8.0 × 2.5–3.0 mm, yellow or yellowish white, with short glandular hairs; anther oblong, 1.3–1.5 × 0.2–0.3 cm, yellow, glabrous; anther crest trilobed, 3.0–3.5 × 8.0–9.0 mm, yellow, glabrous; style filiform, white, glabrous; stigma calathiform, yellowish white, glabrous; ovary elliptic, trilocular with shallow edges, 0.6–0.7 × 0.3 cm, purple-red, densely pubescent; epigynous glands two, oblong, 4.0–5.0 × 1.5 mm, light olive brown, glabrous. Fruit globose, 9-winged, 1.4–2.5 × 1.5–2.2 cm, purple-red, densely pubescent, apex with persistent calyx, wings crisped; seeds with edges and corners, ca. 2 × 3.5 mm, brown, arillate white.

Etymology: —The specific epithet refers to its locality, Xizang Autonomous Region in China.

Distribution and preliminary IUCN assessment: — Amomum xizangense is endemic to Xizang, China. It is known only from 3 localities including the type locality. Its habitat is declining due to various activities such as deforestation and road building. Therefore, we propose to treat this species under ‘Endangered’ (EN) category (B 1 ab (iii)) according to the IUCN (2020) guidelines.

Chinese name: —Ḇķj蔻 (mò tuō dòu kòu)

Additional material examined (paratypes): — CHINA. Xizang, Medog County: Beibeng Xiang , in forest, elev. ca. 830 m, 10 August 1974 , Qinghai - Tibet Expedition 1700 ( KUN 0424111 ); Beibeng Xiang, Jiangxin Cun , in forest edge, elev. ca. 900 m, 8 July 1980 , Eco-plateau Group 11020 ( PE 01376860 ); Nigulong , by the stream under the forest, elev. ca. 900 m, 30 January 1983 , Bo-Sheng Li & Shu-Zhi Cheng 03552 ( PE 01376861 , 01376862 ); Beibeng Xiang , in slope, elev. ca. 1000 m, 10 October 1992 , Hang Sun et al. ( ETM) 0312 ( KUN 0424112 , 0424113 ) .

Figures

FIGURE 1. A. Habit. B. Cross section of stem. C. Leaf sheaths. D. Lateral view of ligule and petiole. E. Front view of leaf sheath and ligule. F. Front view of inflorescence. G. Lateral view of inflorescence. H. Infructescence. I. Inflorescence with scales on the peduncle. J. Inflorescence with scales removed. K. Two flowers with one bracteole and one detached fertile bract (right). L. Back and lateral view of bracteole. M. Dissection of a flower, showing calyx, 3 detached corolla lobes, labellum, pistil, stamen, staminodes, epigynous glands and ovary. N. Lateral view of flower with calyx and corolla lobes removed. O. Front view of pistil, stamen and 2 staminodes. P. Epigynous glands and ovary. Scale bar = 1 cm.