Hedychium viridibracteatum X.Hu, 2018

Hu, Xiu, Huang, Jia-qi, Tan, Jia-chuan, Yong-qingWu, & Chen, Juan, 2018, Hedychium viridibracteatum X. Hu, a new species from Guangxi Autonomous Region, South China, PhytoKeys 110, pp. 69-79 : 71-76

Hedychium viridibracteatum X.Hu sp. nov. Figures 1 , 2 , 3

Diagnosis.

Hedychium viridibracteatum X.Hu, sp. nov. is morphologically similar to H. villosum Wall. var. tenuiflorum Voigt ex Baker by having sagittate anther, long filament, relatively thick and small leaves, more than two flower per-bract, but can be easily distinguished from it by its green (vs. brown) shorter bracts (1.3-1.5 × 0.4-0.5 cm vs. 2.7-2.9 × 1.1-1.2 cm) and bracteoles (1.0-1.1 × 0.3-0.4 cm vs. 2.1-2.2 × 0.7-0.75 cm), pure white flowers (vs. white with red stamen), dentate (vs. acute) tips to the lateral staminodes, and the apex of the labellum incised to the middle (vs. deeply divided).

Type.

China, Zhuang Autonomous Region, Napo county, Nongyi village, on rocks, 22°57.727'N, 106°00.265'E, alt. 696 m, 6 October 2011, Xiu Hu 267 (holotype: IBSC; isotype: MO).

Description.

Epilithic, evergreen perennial rhizomatous herbs. Rhizome purplish brown outside, sheathed, creamy white inside, 2-4 cm in diameter. Leaf stems slender, 60-100 × 0.5-0.7 cm, glabrous, 7-10 leaves. Ligule oblong-ovate, green or purple, glabrous, 1.8-2.3 cm × 1.2-1.5 cm, membranous. Leaf blades elliptic,15-25 × 5-8 cm, base attenuate into a short petiole, 0.5 cm long, apex caudate, glabrous on both sides and dark green above, purple beneath, especially the leaves in the lower part of the stem. Inflorescence a terminal spike, erect, 10-15 cm long, lax flowered; peduncle 1.5-2.0 cm long, green; rachis green, pubescent. Bracts oblong-ovate, apex acute, green, 1.3-1.5 × 0.4-0.5 cm, coriaceous, pubescent outside, glabrous inside, 2-4 flowered. Bracteoles tubular, apex acute, green, coriaceous1.0-1.1 × 0.3-0.4 cm, pubescent outside, glabrous inside. Flowers pure white, 10-11 cm long, lightly fragrant. Calyx tubular, green, 2.5-2.8 × 0.12-0.15 cm, apex obtusely 3-toothed, pubescent. Floral tube pure white, 4.0 -5.0 cm long, slender; lobes glabrous, pure white, reflexed, linear, dorsal lobe 3.1-3.3 × 0.12 cm, lateral lobes 2.9-3.1 × 0.12 cm. Lateral staminodes linear-ridged, pure white, 3.0-3.3 cm long, dentate at apex. Labellum ovate, pure white, 2.8-3.0 × 1.2-1.4 cm, base attenuate into a claw, 0.8-1.0 × 0.2 cm, apex incised to the middle, white. Filament 6.0-6.8 cm long, white; anther dorsifixed, sagittate, 3.5-4 mm long, glabrous, light yellow. Ovary 0.4-0.5 × 0.2-0.4 cm, densely silky hairy, trilocular, placentation axile; epigynous glands 2, slender, ca. 0.2 cm long, yellow. Stigma green, ciliate. Tetraploid.

Flowering.

September–October.

Fruiting.

Unknown.

Etymology.

The new species is named after its green bracts and pure white flowers which are highly diagnostic.

Habitat.

This species is currently found on limestone rocks in Guangxi Autonomous Region (Napo, Longzhou and Jingxi Counties) mainly growing under forest at altitudes of 600-800 m.

Ploidy level analysis.

The results (Fig. 4 ) show that, when the nuclei of the diploid control (Fig. 4A ), Hedychium coronarium ( Hu et al. 2011; Ramachandran 1969) were set to channel 50, the new plant, H. viridibracteatum X.Hu (Fig. 4B ) resolved at channel 100. This means that the new plant is a tetraploid which shares the same level of ploidy with H. villosum Wall. var. tenuiflorum Voigt ex Baker (Fig. 4C ) but differs from H. villosum var. villosum Wall. (Fig. 4D ).

Distribution.

In addition to the type location, the new species is found in the adjacent area, Longzhou and Jingxi Counties (Fig. 5 ). Hedychium viridibracteatum can be easily distinguished from related species, even from dried specimens. The following sites were discovered by examining specimens and confirmed by our field investigations from 2012-2017: 20 September 1935, X. P. Gao 55777, Guangxi Autonomous Region, Jingxi County, Ande district (IBSC 0022836); 13 September 2007, W. B. Xu & Y. Y. Liang 0144, Guangxi Autonomous Region, Jingxi County, Bangliang National Nature Reserve (IBK 00223131); 29 September 2007, W. B. Xu & Y. Y. Liang B0065, Guangxi Autonomous Region, Jingxi County, Bangliang National Nature Reserve (IBK 00223137); 16 September 2010, Y. S. Huang et al. LYJX0450, Guangxi Autonomous Region, Jingxi County, Bangliang National Nature Reserve (IBK 00224854); 27 October 2010, W. H. Wu W0286, Guangxi Autonomous Region, Longhzhou county, Nonggang National Nature Reserve (IBK 00216857).

Other Hedychium spp. examined

Hedychium villosum Wall. var. tenuiflorum Voigt ex Baker

CHINA. Guangxi: Baise County: Daleng, 800 m, 26 Mar 1975, D. Fang 36943 (GXMI); Longguang, 900 m, 14 Jan 1956, Baise Group 1914 (IBK); Longlin County: Dee, Yanyu, 933 m, 9 Sep 1977, J.F. Wei & D. Fang 3-1145 (GXMI); Longlin County: Zhelang, Hanshan, 1000 m, 24 Mar 1975, D. Fang 25610 (GXMI); Longzhou County: Binqiao, Anzhen village, 273 m, 29 Apr 1956, Y.K. Li 212 (IBK); Napo County: Pingmeng, Mengda, back Mountain, 600 m, 16 Apr 1976, D. Fang 22291 (GXMI); Pingmeng, Nonghua to Sheng village, 700 m, 12 May 1989, South China team 702 (IBSC); Pingmeng, Nongyi, Stone Mountain, 646 m, 1 Mar 2006, M. Liu 3 (HITBC); Nanning County: Maoqiao, Medicinal Garden, 80 m, 3 Mar 1975, D. Fang & X.X. Chen 78882 (GXMI); Shangsi County: Fenghuang, Longshan Mid-range, 811 m, 4 Mar 1944, S.Q. Chen & S.H. Chun 4628 (IBSC); Fulongai, back valley, 607 m, 23 May 1966, T.J. Wang 5393 (GXMI); Tiandeng County: Fuxin, Miao village, 502 m, 18 Sep 1977, Tiandeng County Investigation Team 2-233 (GXMI); Hainan: Changjiang County: Bawang Mountain, Dongsi Forest Farm, 1400 m, 20 Apr 1988, Z.X. Li & F.W. Xing 3526 (IBSC); Bawang Mountain, Dongwu Forest Farm, 1015 m, 27 Mar 1983, G.Y. Fu 3418 (IBSC); Baoting County: Diaoluo Mountain, Xin’an village, 84 m, 24 Dec 1954, Diaoluo Mountain Team 3280 (IBSC); Qizhi Mountain, 185 m, 9 Jan 1934, Z. Huang & C. Wang 36223 (IBSC); Jianfeng Mountain, 830 m, 15 Apr 1982, Q. Huang 820154 (IBSC); Xizang: Motuo County: Damu to Gedang, 850 m, 25 Mar 1993, H. Sun & Z.K. Zhou & H.Y. Yu 5043 (KUN); Yunnan: Fugong County: Pihe, east coast of Nu River, 1100 m, 30 May 1978, Bijiang Investigation Team 0257 (KUN); along Nu River, Stone Mountain, 1262 m, 9 Apr 2008, F. Yu 19 (HITBC); Diao Ga Guo Zhai, 25 Apr 2004, D. Heng 49837 (GH); Funing County: Banlun, 728 m, 10 Apr 1940, Q.W. Wang 88283 (KUN); Gengma County: 1670 m, 1 Apr 1936, Q.W. Wang 72918 (IBSC); along the Gengma River, 1280 m, 7 Mar 2008, F. Yu 20 (HITBC); Gongshan County: Dulongjiang, Longyuan, 1772 m, 12 Apr 1994, Dulongjiang Investigation Team 5582 (KUN); Hekou County: Dawei Mountain, Laozhai, 1338 m, 6 Mar 1940, X. Wang & X.P. Gao & X.Q. Liu 100235 (IBSC); Qiaotou, 958 m, 1 Apr 2008, F. Yu 21 (HITBC); Jingdong County: Dongchuan River, 1097 m, 26 Mar 1940, M.G. Li 1900 (KUN); Wuliang Mountain, 1500 m, 19 Mar 2008, F. Yu 22 (HITBC); Jinghong County: Damenglong Mengsong Mountain, 1800 m, 29 Nov 2006, S.S Zhou 3409 (HITBC); Liuku County: Nu River, along the road, 1241 m, 8 Apr 2008, F. Yu 18 (HITBC); Mang County: Mengjiu, 1601 m, 28 Jul 1984, Q.G. Wu 96 (IBSC); Lvchun County: Huanglianshan national Nature Reserve area, 1500 m, 28 Apr 1984, S.Q. Dong & A.M. Li 24905 (HITBC); Malipo County: Huangjinyin, 1455 m, 13 Jan 1940, Q.W. Wang 83189 (KUN); Nanwen River, Laojun Mountain, 1600 m, 1 Jun 1983, S.Q Dong 32927 (HITBC); Menghai County: Mengsong, Manjin, 1221 m, 27 Mar 1957, Zhongsu Team 5469 (IBSC); Mengla County: Menglun Tropical Botanical Garden, 564 m, 25 Jan 2007, L.Q. He 119 (HITBC); Xiangming, 900 m, 26 Mar 1984, S.Q. Dong & A.M. Li 24897 (HITBC); Pingbian County: 1677 m, 9 Mar 1934, Y. Qian 13443 (IBSC); Yanshan County: Shuitouzhai, 1200 m, 19 Oct 1939, Q.W. Wang 84527 (KUN); Yingjiang County: Tongbiguan, 1400 m, 9 Apr 1985, Examination Team 85-200 (KUN); Zhenkang County: Bainiu village, 1593 m, Mar 1936, Q.W. Wang 72237 (KUN).

Hedychium villosum var. villosum Wall

CHINA. Yunnan: Fugong County: Maji Township, 1337 m, 4 Nov 1990, Dulong River Investigation Team 140 (KUN); Gongshan County: Dulong River to Meilin River, 1400-1420 m, 11 Jul 1979, Q. Lin & X.F. Deng 2731 (KUN); Dulong River East Coast, 2200-2400 m, 20 Sep 1940, G.M. Feng 2168 (KUN); Dulong River West Coast, 1300 m, 20 Nov 1990, Dulong River Investigation Team 637 (KUN); Dulong River West Coast, Four village, 1300 m, 25 Nov 1959, G.M. Feng 24396 (KUN); Mengla County: Menglun, 800 m, 6 Dec 1972, Y.H. Li 8466 (HITBC); Menglun, 26 Jan 1979, J.Y. Cui 14683 (HITBC); Menglun, Silver Factory, limestone mountains, 860 m, 6 Jan 1960, Y.H. Li 2731 (HITBC); Menglun, limestone mountains, 1200 m, 23 Nov 2005, S.S. Zhou 3320 (HITBC); Mengyuan, Nov 1982, Expedition team 34279 (HITBC); Shangyong, 900 m, 18 Oct 1974, Z.H Yang 10983 (HITBC); Yiwu Dt.: Manpi, 1000 m, 8 Sep 1959, S.J. Pei 9993 (HITBC); Menglian County: 957 m, 2 Oct 2006, X. Hu 001 (IBSC).

Figures

Figure 1. Hedychium viridibracteatum X. Hu, sp. nov., holotype, A upper leaves and inflorescence B flower C bract D ovary and glands E calyx tube F floral tube with calyx tube wrapped outside G corolla lobe H lateral staminodes I labellum J stamen K anther L stigma. Drawings Y. X. Liu.

Figure 2. Hedychium viridibracteatum X. Hu, sp. nov., flowers and their parts: A bract B bracteole C ovary D calyx tube E floral tube F corolla lobe G lateral staminodes H labellum I labellum claw J filament K anther.

Figure 3. Hedychium viridibracteatum X. Hu sp. nov. A habit (growing on rocks) B rachis and bracts (pubescent) C ligule (glabrous) D inflorescence at anthesis E leaf blade surface (adaxial view) F leaf blade surface (abaxial view) G rhizome H portions of inflorescence (2 - 4 flowers per bract).

Figure 4. Histogram of relative DNA content of nuclei isolated from the leaves of the new plant and related Hedychium species. A H. coronarium (control) B H. viridibracteatum C H. villosum var. tenuiflorum D H. villosum var. villosum.

Figure 5. Distribution and flowering of Hedychium viridibracteatum X. Hu, sp. nov. and the related species H. villosum var. tenuiflorum and H. villosum var. villosum.