Phylogenetic and biogeographical analyses of Thismia (Thismiaceae) support T. malipoensis as the eighth species in China Ya, Ji-Dong Chen, Hai-Yao Zhang, Wei Zhu, Ren-Bin Cai, Jie Yu, Wen-Bin Willdenowia 2024 2024-02-28 54 1 47 63 J. D. Ya & W. B. Yu J. D. Ya & W. B. Yu 2024 [151,593,617,641] Liliopsida Burmanniaceae Thismia Plantae Dioscoreales 9 55 Tracheophyta species malipoensis sp. nov.  – Fig. 1–4.    Holotype: China, Yunnan Province, Wenshan Prefecture, Malipo County, Tianbao Town,  1191 ma.s.l., forest on limestone,  13 Aug 2019,  J.-D. Ya& W. Zhang19CS18569( KUN 1584483!).   Diagnosis — Thismia malipoensisbelongs to  T.sect.  Glaziocharisand can be distinguished from its phylogenetic sister species  T. abeiby having the annulus of the flower expanded and modified into a cucullate (hood-like) structure with zygomorphic symmetry with one opening on one side. Moreover,  T. malipoensiscan be distinguished from the morphologically similar  T. belumensis, in that the outer and inner tepal appendages are spreading (vs erect) and equal in length by less than 2 cm(vs outer tepal appendage 1.5–2.5 cmand inner tepal appendage c. 3 cm), the inner tepal base is fimbriate at the margin (vs entire) and the inner tepal tip is subulate (vs clavate).   Description — Herbsterrestrial, achlorophyllous, c. 7 cmtall. Rootsvermiform, creeping, branched, fleshy, terete, pale brownish. Stemserect, unbranched, 2–4 cmlong, densely deflexed papillate hairy. Leavesscale-like, white, translucent, lanceolate, c. 8 × 2 mm, base appressed to stem, apex acuminate. Involucral bracts3, pale brownish, lanceolate, c. 1 cmlong, densely deflexed papillate hairy, base appressed, margin entire, apex acuminate. Pedicelc. 3 mmlong (post anthesis). Flowersterminal, solitary, zygomorphic, c. 4.5 × 4 cm(including appendages); hypanthiumpyriform, dark green, translucent, c. 8 mmlong, c. 7 mmwide near apex, narrowed to c. 4 mmwide just above ovary, outer surface densely deflexed papillate hairy, with 12 raised dark brown longitudinal veins, inner surface smooth; outer tepals3, pale brown, broadly ovate, c. 2.5 × 3 mm, 2 on opposite side of annulus opening and 1 below annulus opening, outer surface sparsely papillate, apex acute, each outer tepal with a tentacle-like spreading appendage, pale brown, 0.8–1.3 cm× c. 1 mm; inner tepals3, pale brown, translucent, glabrous, broadly obovate, c. 3.5 × 4 mm, apically broadly fused and tightly adpressed and completely overlapping cucullate part of annulus, each inner tepal with a tentacle-like spreading appendage c. 1.7 cmlong, pale brown, fimbriate at basal margin, subulate at apex. Annulusexpanded and modified into a cucullate (hood-like) structure, covering apical part of floral tube and forming a lateral floral aperture; cucullate outer surface white with 3 brown lines, glabrous; cucullate inner surface light green, covered with numerous white trichomes. Stamens6, light yellow, pendent from apical part of floral tube; each connective c. 3.5 mmlong, outer surface with 2 linear to filiform thecae, each c. 2 mmlong, inner surface smooth, outer surface and apex covered with transparent trichomes; supraconnective apex rounded and curved outward; filaments short, connected to floral tube and annulus. Ovaryobovoid, c. 3.5 × 4.8 mm, 1-loculed, with 3 parietal placentae; style c. 0.6 mmlong; stigma 3-lobed, lobes triangular-pyramidal, c. 1.2 mmlong, apex truncate and densely papillate.  Fruitcup-shaped; seeds brown.   Phenology— Observed flowering in August, fruiting in September.   Distribution and habitat — Thismia malipoensisis currently known only from the typelocality in Laoshan Provincial Nature Reserve of Malipo County, SE Yunnan. The population consists of about ten individuals under evergreen broad-leaved forest on limestone mountains at an elevation of 1191 ma.s.l. The forest includes the  Lithocarpus tephrocarpus(Drake) A. Camus(  Fagaceae),  Alseodaphnopsis andersonii(King ex Hook. f.) H. W. Li & J. Liand  Litsea yunnanensisY. C. Yang & P. H. Huang(both  Lauraceae) and the bamboo  Melocalamus arrectusT. P. Yi.   Etymology— The specific epithet “ malipoensis” refers to the county name Malipoof Wenshan Prefecture, the typelocality of the new species.    Chinese name—  B栗坡水玉杯(má lì pō shuǐ yù bēi).   Conservation status— We evaluated the conservation status of  Thismia malipoensisaccording to the IUCNRed List categories and criteria ( IUCN Standards and Petitions Committee 2022). The new species is known only from the typelocality, our field surveys identified only one population with about ten individuals. The conservation status of the species is therefore considered to be Critically Endangered ( CR A2acd; B1ab(i,iii,v)+2ab(i,iii,v); C2a(i); D). 5225708301 2019-08-13 KUN J. - D. Ya & W. Zhang China Malipo County 1191 Tianbao Town Wenshan Prefecture 9 55 1584483 1 Yunnan Province holotype