Helonias yunnanensis var. yunnanensis

Tanaka, Noriyuki, 2019, Taxonomy, evolution and phylogeography of the genus Helonias (Melanthiaceae) revisited, Phytotaxa 390 (1), pp. 448-450 : 448-450

2a. Helonias yunnanensis var. yunnanensis ( Fig. 7 ).

= Ypsilandra yunnanensis var. micrantha Handel-Mazzetti (1923: 155) . Type (lectotype, designated here):― CHINA. NW Yunnan. In regione frigide temperata jugi Nisselaka inter fluvios Mekong et Salween , 28°, s. micoschistaceo, ca. 4175 m, in palude, 18 June 1916, Handel-Mazzetti 8962 (WU-61254*!).

= Ypsilandra yunnanensis var. himalaica H. Hara in Hara et al.(1978: 80). Type :―C. NEPAL. Rambrong, Lamjung Himal, 13,500 ft, 3 July 1954, Stainton, Sykes & Williams 6090 (Holotype: BM-521481*! Isotype: E-00318414*!; P-01724142*! p.p.).

Description:―Rhizome cylindrical, vertical or ascending, nodose, 0.7–2.5(–4) cm long, 0.4–1.2 cm in diam. Roots filiform, to 1.8 mm in diam., whitish, often contractile. Leaves slightly hysteranthous, main fresh rosette leaves 5–13, persistent for ca. 1 year, spatulate or oblanceolate, 2.5–15(–22) cm long, 0.6–2.2 cm wide, tapering to cuneate base, margins sometimes revolute, apex acute, apiculate, apiculus 0.3–0.4(–1) mm long. Flowering stem 2–21 cm long at anthesis, elongating to 62 cm long in fruit; peduncle 1.5–18 cm long, elongating to 55.5 cm long in fruit; scale-like leaves on peduncle (excl. basal ones) few to several (or sometimes many), narrowly lanceolate, oblong-lanceolate, narrowly elliptic or oblanceolate, to 3.8 cm long; inflorescence racemose, ovoid or cylindrical-ovoid; rachis 0.3–4 cm long at anthesis, elongating to 2.8–7.5(–10) cm long in fruit; pedicels 0.3–2.5(–6) mm long at anthesis, becoming antrorse and 2–8 mm long in fruit, ebracteate, the lowermost rarely bracteate. Flowers 3–28, usually 3.5–8 mm across, facing upward, spreading horizontally or downward (depending on position on rachis), adichogamous, fragrant, nodding at late anthesis. Tepals 6, (narrowly) elliptic, oblanceolate, obtuse or subacute, 2.5–5.5(–7) mm long, 1.5–2.8 mm wide, white, pale to dark lilac, bluish, light violet purple, purple, veins (3 or) 5. Stamens 6, usually shorter than tepals, sometimes equaling or slightly exserted beyond tepals; filaments 1.5–4.5 mm long, apex short acuminate, white or purple; anthers reniform, basifixed, 0.5–1 mm long, dark purple or blue (sometimes darker along suture of sac). Pistil 1, 2–3 mm long, included in perianth, equaling or shorter than stamens; ovary globose, apex emarginate, trilobed, green or dark purplish green, 2–2.5 mm long, 2–2.3 mm across; style 0.2–1.2 mm long; stigma trisected, segments narrowly ligulate, 0.7–1.5 mm long, recurved, white or greenish white; ovules 18–79 per locule, multiseriate on central axile placentae. Capsules facing upward, broadly obpyramidal or obovoid (cordate in lateral view), apex usually depressed in center, tripartite, 4–5.5 mm long, 5–12 mm across, lobes ovoid-conic, apically rounded, ascending to horizontally divergent. Seeds many, with pale brownish testa, narrowly fusiform, 2.7–5 mm long, 0.4–0.6 mm broad, proximally sublinear, distally caudate or subulate; body of seed narrowly oblong, brown, 1.2–1.8 mm long, 0.3–0.5 mm wide.

Additional specimens examined:― BHUTAN. Me La, 14,000 ft, 15 September 1949, fr., Ludlow et al. 21189 (BM-001118031); Pang La, 11,000 ft, 9 July 1949, Ludlow et al. 20862 (E-00902974 *, BM-001118030). CHINA. Xizang (S.E. Tibet): Kongbo Prov., Tum La, Nayü, Lat. N. 29°0’, Long. E. 94°0’, 12,000 ft, 7 July 1938, Ludlow et al. 5775 (BM-001118040); ibid., 11,000 ft, 9 July 1938, fr., Ludlow et al. 5798 (BM-001118034); Lusha Chu, 12,500 ft, 9 June 1938, fl., Ludlow et al. 4740 (BM-001118035); Pachakshiri Distr., Lo La, 9500 ft, 8 October 1938, F. Ludlow 6566 (BM-001118039); Lo La, 10,000 ft, 4 April 1938, fl., Ludlow et al. 3651 (BM-001118037); Ponu, above Trung, 13,000 ft, 26 June 1947, fl., Ludlow et al. 13210 (BM-001118036). Yunnan: Deqen Xian, Cizhong, 3650 m, 4 July 1940, K.M. Feng 5107 (PE-00593986); Deqen Xian, Cizhong, 3650–3700 m, 4 July 1940, K.M. Feng 5109 (PE-00593987*, KUN); Fugong Xian, Gaoligongshan Region, 3560 m, 12 August 2005, fr., Gaoligongshan Biodiversity Survey 27019 (GH-00293355); Fugong Xian, Pi-he, elev. 3417 m, 15 May 2008, X.H. Jin & T. Zhang 054 (PE-01944105*); Gongshan Xian, Cikai Zheng, 3400 m, 17 July 2000, H. Li et al. 12765 (GH); Gongshan, Bingzhongluo, 4270 m, 28 August 2006, fr., Gaoligongshan Biodiversity Survey 31512 (GH-00293671); Mekong-Salwin divide, 12,000 ft, September 1917, G. Forest 14961 (E-00115516); Salwen-Mekong divide, 13,000 ft, June 1911, F. Kingdon-Ward 163 (lectoparatype of Ypsilandra yunnanensis , E-00346116); Mekong-Salwin Divide, Londjrela, 3900 m, 9 October 1938, fr., T.T. Yü 22893 (A); ibid., Sila, 4000 m, 19 August 1938, fr., T.T. Yü 22420 (A); In regione frigide temperatae jugi Si-la inter fluvios Mekong et Salween, 28°, s. micoschistaceo, ca. 3900 m, in paludibus pascui Dotitong, 18 June 1916, Handel-Mazzetti 8949 (lectoparatype of Ypsilandra yunnanensis var. micrantha , WU-61254*); Open pasture on the western flank of the Shweli-Salween divide, lat. 25°20’ N, elev. 10,000 –11,000 ft., August 1912, G. Forrest 8956 (lectoparatype of Ypsilandra yunnanensis , E-00346115*, K-000400241*); no detailed locality, no date, fl., G. Forrest 14158 (K); Mountains above Tseku and Tsehchung, Mekong-Salween watershed, June 1923, fl., J.F. Rock 9121 (P-01619474*); Mountains above Tsehchung, 11,000 ft, July 1923, fl., J.F. Rock 10091 (E-00115517, GH); without detailed locality, 25°45’ N, 98°40’E, 10,000 ft, Jun. 1924, G. Forrest 24438 (K, p.p., right plant only, left plant is Theropogon ; PE-00593995*). INDIA. Assam, Delei Valley, fl., Kingdon-Ward 8230 (K). MYANMAR. N. Burma. Tama Bum, 10,000 –10,500 ft, 27 June 1953, Kingdon-Ward 21196 (BM-001118038); North and Upper region, 11,000 ft, June 1924, early fr., G. Forrest 24654 (K, PE-00593996*); Ridge of Naung-Chaung-Nwai divide, Burmo-Chinese frontier, elev. 11,000 –12,000 ft., 16 July 1914, Kingdon-Ward 1808 (lectoparatype of Ypsilandra yunnanensis , E-00318415*); Upper Burma, 1924–25, G. Forrest 26906 (P-01619476*). NEPAL. Kaski District, south of Annapurna. ca. 4300 m, 23 May 1972, fl., R. G. Troth 219 (TI); E. Nepal, Kasawa Khola, 14,000 ft, 1 June 1974, fl., Stainton 7063 (TI); Kasuwa Khola, 13,000 ft, 21 August 1975, fr., L.W. Beer 25356 (BM-001118029, TI); Koshi Zone, Sankhuwa Sabha Distr., 30 July 1988, fr., M. Suzuki et al. 8821028 (BM-001118033, TI); E. Nepal, Koshi Zone, Sankhuwasabha Distr., 3940 m, 27 August 1997, fr., S. Noshiro et al. (TI).

Distribution:― Bhutan, China (SE Xizang, NW Yunnan), India (Assam), Myanmar (northern border with China), Nepal (Central, E) (Fig. 15-Yy).

Habitat:―By streams, open moist alpine meadows, shady thickets at elevations ca. 2700–4300 m.

Conservation status:―The species is comparatively widespread, and may be assessed as LC according to the IUCN Red List Categories and Criteria (2001).

Flowering:―April–July.

Ripening:―June–October.

Remarks:― Ypsilandra yunnanensis var. micrantha or var. himalaica , a dwarf form in Bhutan, Nepal and Tibet passes into var. yunnanensis ( Fig. 7 ) and hence is not distinguishable ( Tanaka 1998a). The dwarf form appears to be an adaptation to harsh alpine environments. The stamens of Helonias yunnanensis var. yunnanensis are usually shorter than the tepals ( Fig. 7B, D, E ), but a form with stamens equaling or slightly exceeding the tepals and with somewhat longer pedicels, to ca. 6 mm long (e.g. Ludlow et al. 3651, 5775, 5798 at BM, cited below under China), is in southeastern Tibet. I regard this form as a local race, since it appears to gradually pass into var. yunnanensis .

Figures

FIGURE 7. Helonias yunnanensis var. yunnanensis. A. Habit and habitat (Y-1; photo on 24 May 2014). B. Closeup of inflorescence (Y-1 on 24 May 2014). C–E. Isolectotype (G. Forrest 12055, E-00115522). C. Habit. D, E. Closeup of inflorescence. F. Part of infructescence with dehisced capsules (G. Forrest 14961, E-00115516). G. Seeds (Gaoligongshan Biodiversity Survey 27019, GH-00293355). Photos A & B by Yang Niu.