Paphiopedilum barbigerum Tang & Wang (1940: 23) var. barbigerum, Cribb (1998: 234) Paphiopedilum insigne

Averyanov, Leonid V., Nguyen, Van Canh, Vuong, Truong Ba, Nguyen, Khang Sinh, Nuraliev, Maxim S., Nguyen, Cuong Huu, Ormerod, Paul A., Maisak, Tatiana V., Diep, Dinh Quang, Lyskov, Dmitry F. & Nong, Duy Van, 2023, New orchids in the flora of Vietnam VII (Orchidaceae: tribes Cypripedieae, Cranichideae, Orchideae, and Collabieae), Phytotaxa 619 (4), pp. 255-276 : 257

Paphiopedilum barbigerum Tang & Wang (1940: 23) var. barbigerum, Cribb (1998: 234) ,

Averyanov (2008: 72), Braem et al. (1999: 216), Averyanov et al. (2003a: 170). Schuiteman et al. (2008: 302), Chen et al. (2009: 39), Liu et al. (2009: 112), Zhou et al. (2016: 101), s. str. Type: — CHINA. Guizhou Province: Kweichow, Cavalerie & Fortunat 1794 (holotype PE00027273).

( Figs. 1 A–C )

≡ Paphiopedilum insigne (Wall. ex Lindley 1824: tab. 32) Pfitzer (1888: 11) var. barbigerum (Tang & F.T.Wang) Braem (1988: 113) .

Ecology and phenology in Vietnam:—Lithophytic rosulate herb. Primary evergreen broad-leaved submontane forests on marble-like karstic, highly eroded limestone at an elevation of 900–1100 m a.s.l. Very rare. Flowers in September – October .

Distribution:— Vietnam (Son La Province: Thuan Chau District). South China.

Conservation status in Vietnam:—This variety is known in Vietnam in a single location. Given that the duration of a generation equals 3 years, observed population reduction for 10 years or 3 generations is ≥ 80% and is not reversible (A2), based on direct observation (a), observed decline of the area of occupancy, extent of occurrence and habitat quality (b), and actual levels of exploitation (c); the area of occurrence <100 km ² (B1) and the area of occupancy <10 km ² (B2), with 1 known population (a) and continuing observed decline of extent of occurrence (bi); the area of occupancy (bii); area, quality of habitat (biii); the number of mature individuals (bv); the number of mature individuals <250, observed, estimated or projected continuing decline in 25% in 3 years or 1 generation (C1) and observed, estimated, projected or inferred continuing decline with the single population containing 90–100% of mature individuals (C2(ii)). Similarly to all the other varieties of P. barbigerum , the type variety stands presently on the verge of full extinction in nature due to over-collecting for sale. Accordingly, following the formal criteria of the IUCN Standards and Petitions Committee (2023) it is assessed nationally here as Critically Endangered (CR—A2abcd+3abcd+4abc; B1ab(i,ii,iii,v)+2ab(i,ii,iii,v); C1+2a(ii). The number of mature individuals and the habitat decline dramatically and hence, even if there are chances of immigration of propagules, the lack of habitat and the rate of decline would not allow this variety to survive in the wild.

Notes:—According to the presently available knowledge, Paphiopedilum barbigerum is a rare and highly variable species. It is subdivided into six varieties with almost allopatric distribution in southern China ( var. barbigerum ), northern Thailand ( var. lannaense (Tongkham, Pumikong, Potapohn & Bundithya) Schuit. and var. vejvarutianum (O.Gruss & Roellke) Perner ), northern Laos ( var. coccineum (Perner & R.Herrm.) Cavestro and var. sulivongii Schuit. & P.Bonnet ) and in Vietnam. In the flora of Vietnam, two varieties were known prior to this study. They are P. barbigerum var. aspersum (Aver.) Aver. and P. barbigerum var. coccineum (= P. barbigerum var. lockianum Aver. ). The discovery of the type variety in Vietnam reported here represents a new national record, which makes Vietnam the richest country in diversity of this species. In its distribution, this variety is a typical endemic of the South Chinese Floristic Region as outlined by Averyanov et al. (2003a,b).

Studied specimens:— VIETNAM. Son La Province: Thuan Chau District, base of Pha Din Pass , remnants of primary evergreen forest on limestone mountains at elevations of 900–1100 m, 4 October 2022, Lo Trung Van, Khang Sinh Nguyen AL 1605 ( LE01170110 https://en.herbariumle.ru/?t=occ&id=162636, photos LE01123569 https:// en.herbariumle.ru/?t=occ&id=143330) .

Tribe Cranichideae (subfamily Orchidoideae )

Figures

FIGURE 1. Paphiopedilum barbigerum var. barbigerum. A. Flowering plant in natural habitat. B & C. Flowers, front view. Specimen: L.T.Van, K.S.Nguyen AL 1605. Myrmechis urceolata. D. Flattened flowering and fruiting plants. E & F. Apical part of floriferous stem with flowers. G & H. Flowers and flower buds, side and front view. Specimen: T.B.Vuong, N.T.Luan AL 1237. Peristylus affinis. I. Flattened plant. J. Portion of inflorescence. K. Flower, side view. L. Detached flower, side view, with sepals removed. M. Detached flower, sagittal section. N. Detached flattened sepals, petals and lip. Specimen: S.K.Nguyen, T.H.Nguyen, M.H.Giang NSK 950. Photos by L.T.Van & K.S.Nguyen (A–C), T.B.Vuong (D–H) and K.S.Nguyen (I–N); photo correction and design by L.Averyanov and T.Maisak.