Helonias jinpingensis (W.H.Chen, Y.M.Shui & Z.Y.Yu) Tanaka (2009: 190)

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

3. Helonias jinpingensis (W.H.Chen, Y.M.Shui & Z.Y.Yu) Tanaka (2009: 190) .

≡ Ypsilandra jinpingensis Chen et al. (July 2003: 267, fig. 1 on p. 268). Type:― CHINA. Yunnan: Jinping, Mt. Wutaishan , elev. 2660 m, 3 October 1996, S.G. Wu et al. 3742 (Holotype: KUN, n.v.) .

= Ypsilandra yunnanensis W.W.Sm. & Jeffrey var. fansipanensis Shaw (2008: 41) . Type: VIETNAM. Cultivated flowering plant pressed on 2 October 2007, originally collected from Vietnam , Lào Cai province, Mt. Fansipan , 2700 m, 1 December 2006, B. & S. Wynn-Jones 11839 (Holotype: WSY-0100773*! Paratype?: Herb. B. Wynn-Jones, n.v.).

Description:―Description based on Chen et al. (2003) and Shaw (2008):―Rhizome vertical, ca. 1–2 cm long, ca. 7 mm in diam., brown, closely annulate with numerous scars. Roots to 30 cm long, 1–1.5 mm in diam., hirsute. Leaves proteranthous, main fresh rosette leaves 6–9(–ca. 22), oblanceolate, 7–21 cm long including petiole, 1.7–2.5 cm wide, gradually narrowed to petiole, chartaceous. Stem to ca. 45 cm long including terminal young infructescence (in fruit); peduncle 32–36 cm long (in fruit), grooved, with 10 or more narrowly oblong scale-like leaves 1.1–2.3 cm long, 0.2–0.6 cm wide; inflorescence racemose 8–9 cm long (in fruit); pedicels 5–12 mm long (incl. those in fruit), each subtended by narrowly oblong bracts 7–8 mm long, 1.0– 1.2 mm wide. Flowers ca. 10 or more per scape; tepals narrowly oblanceolate or spatulate, 4.5–5.0 mm long, 1.6–2.0 mm wide, 3-veined, white or cream, turning yellowish green with age. Stamens 4.6–5 mm long, equaling or slightly exserted beyond tepals at anthesis, filaments 5–10 mm long, white; anthers broadly oblong, 0.6–0.9 mm long, bright blue; pollen creamy-white. Ovary trilobed apically, trilocular, dark bluish black at anthesis; style 1.3–1.8 mm long; stigma trisected, segments 0.8–1 mm long, recurved. Capsules broadly obpyramidal, apex depressed in center, tripartite, 4.5–5 mm long, ca. 2.2 mm across; lobes protruding obliquely upward. Seeds not seen.

Distribution:―SW China (SE Yunnan), N Vietnam (border with China) (Fig. 15-J).

Habitat:―Moist places in dense forests at elevations 2660–2910 m (fide Shui & Chen 2006, Shaw 2008).

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:―(late August–)September.

Ripening:―October–November.

Remarks:― Helonias jinpingensis appears to be closely allied to H. yunnanensis var. yunnanensis , but has a slightly longer style ( Table 6). Judging from the drawings and description in Chen et al. (2003, as Ypsilandra ), the type specimen of Helonias jinpingensis is already in fruit. A photograph of the young inflorescence is shown in Shaw (2008, as Y. yunnanensis var. fansipanensis ). Helonias jinpingensis is unique in having bracteate pedicels. Supposedly, this character state is an apomorphy, since both H. yunnanensis var. yunnanensis and H. bullata , which are considered to be more primitive in the stylar characteristics, have no floral bracts. Because H. jinpingensis blooms in late summer to autumn (September, and probably also late August, judging from papers by Chen et al. 2003 and Shaw 2008), the leaves are regarded as proteranthous. This also implies that the dormancy of flower buds, which is seen in vernal species of Helonias (e.g. H. thibetica , H. orientalis ), is lost. This feature may also be a derived character state acquired under subtropical or warm-temperate conditions.