Helonias alpina (F.T.Wang & Tang) Tanaka (1998a: 106)

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

4. Helonias alpina (F.T.Wang & Tang) Tanaka (1998a: 106) ( Fig. 10 ).

≡ Ypsilandra alpina Wang & Tang (1936: 81) , ‘ alpinia ’ *. Type:― MYANMAR. Frontier of Tibet and Burma, Seinghku-wang, 28°8’ N, 97°24’E, 14,000 ft, on turf slopes on the exposed flanks of a limestone ridge, 9 July 1926, F. Kingdon-Ward 7084 (Holotype: K-000400242*! Isotype: E-00115520!). * The epithet ‘ alpinia ’ is obviously a printing error, for the specimen was annotated by the authors (December 1935) as Y. alpina .

Description:―Rhizome cylindrical, 1–1.3 cm long, 0.3–0.6 cm in diam. Roots filiform, to 1.5 mm in diam., whitish or pale brown (in sicco), contractile. Leaves slightly hysteranthous, main fresh rosette leaves 4–11, narrowly oblanceolate, to 6 cm long, to 1 cm wide, apex acute, minutely apiculate. Flowering stem to 6 cm long; peduncle to 5.5 cm long; scale-like leaves oblong-ovate to lanceolate, acute, imbricate, (sub)herbaceous; inflorescence racemose, compact, rachis 2–5 mm long; pedicels 0.5–2 mm long, ebracteate. Flowers 2 to 5 or 6 per inflorescence, mostly facing upward, few sideward, campanulate or funnelform, ca. 0.8–1.1 cm across, fragrant. Tepals narrowly oblong or narrowly oblong-oblanceolate, 8–12 mm long, (1.5–)2–3(–3.3) mm wide, apex rounded, 3–5(–6)-veined, violet or chocolate in color. Stamens slightly shorter than tepals and nearly equaling (or slightly shorter or higher than) pistil; filaments 6–9 mm long, straight; inner filaments adnate basally to ovary; anthers ovate-reniform, unilocular, basifixed, 0.8–1 mm long, white. Pistil 1, 6.5–9 mm long; ovary globose, longitudinally trisulcate, 3 mm long and broad; style columnar, somewhat thick, 3.5–6 mm long; stigma trisected, white, segments 0.5–0.9 mm long, recurved. Fruit and seeds not seen.

Additional specimen examined:― MYANMAR. Frontier of Tibet and Burma, Seinghku-wang, 28°8’ N, 97°24’E, 13,000 ft, 9 July 1926, fl., F. Kingdon-Ward 7083 (BM-001118047) .

Distribution:―N Myanmar (Fig. 15-A).

Habitat:―Turf slopes and level stretches of turf among boulder heaps in valleys at elevations 3962–4267 m (Kingdon-Ward 7083, BM; Kingdon-Ward 7084, E).

Conservation status:―The range is narrow and the population size is supposedly small. Preliminarily assessed as DD according to the IUCN Red List Categories and Criteria (2001).

Flowering:―June–July.

Remarks:― Helonias alpina appears to be most closely allied to H. yunnanensis var. mesostyla ( Figs. 8 , 9 ) in having comparatively long styles and short stigmatic segments. The ranges of H. alpina (Fig. 15-A) and H. yunnanensis var. mesostyla (Fig. 15-Ym) are close to each other, which may also suggest their close phyletic relationship. Helonias alpina is distinguishable from H. yunnanensis var. mesostyla by the larger flowers with longer oblong or oblong-oblanceolate tepals, and longer filaments and styles. The anthers of H. alpina are not exserted beyond the tepals ( Fig. 10 ), while those of H. yunnanensis var. mesostyla are equaling or slightly exceed the tepals ( Figs. 8 , 9A ). The stigmatic segments of the latter appear to be relatively slightly longer than those of H. alpina ( Table 6). Chen (1980) and Chen & Tamura (2000) reported Ypsilandra alpina from SE Xizang (Tibet) and NW Yunnan, China, but I have not yet confirmed its occurrence in the regions on a specimen basis. Chen identified specimens T.T. Yü 19283 (PE-00035447*!, PE-00593847*!, PE-00593848*!) from NW Yunnan as H. alpina ( Ypsilandra alpina , ‘ alpinia ’) according to his annotations (dated May 1975) on the specimens. However, these belong to H. yunnanensis var. mesostyla in the present circumscription. Since the type specimens of H. alpina were collected in the frontier of Tibet and Burma (F. Kingdon-Ward 7084, E, K), there is a good possibility that it also occurs in SE Xizang and/or NW Yunnan. Helonias alpina is viewed as an alpine, (semi-)dwarf form with somewhat large flowers derived from H. yunnanensis var. mesostyla . To more clearly elucidate their relationship, it is necessary to conduct further surveys on the variation of the two taxa based on more samples.

Figures

FIGURE 8. Helonias yunnanensis var. mesostyla from N Myanmar (Kermode 17139, holotype, K-001235138). A. Habit. B, C. Closeup of inflorescence.

FIGURE 9. Helonias yunnanensis var. mesostyla. A. Flower with frontal tepal and stamen removed.B. Pistil.C. Fruit with persistent floral parts. One frontal tepal removed. D. Two seeds. A, B from N Myanmar (Kermode 17139, holotype, K-001235138). C, D from Yunnan, China (Gaoligongshan Biodiversity Survey 32015, GH-00292433). Scale on right corner for B and D. Drawn by Noriyuki Tanaka.

FIGURE 10. Helonias alpina from SE Tibet (F. Kingdon-Ward 7084). A, B. Habit. C–E. Closeup of inflorescence. A–D: Holotype (K- 000400242*). E: Isotype (E-00115520). Stigmas arrowed in E.