Hemipilia zhuxiensis Hong Liu, 2024

Shen, Cai-quan, Lu, Gui-Hua, Chen, Xi-Tang, Yi, Li-Sha, Lan, De-Qing, Qin, Rui & Liu, Hong, 2024, Hemipilia zhuxiensis (Orchideae, Orchidaceae), a new species from Hubei Province, China, PhytoKeys 247, pp. 203-217 : 203-217

Hemipilia zhuxiensis Hong Liu sp. nov.

Figs 3 , 4 , 5

Type.

China. • Hubei: Zhuxi County, Shibali Long Canyon National Nature Reserve ; 733 m; 18 June 2020; HSN 13099 (holotype: HSN). To protect this species, the exact latitude and longitude are not published .

Diagnosis.

Though apparently similar to H. henryi Rolfe and H. crassicalcarata S. S. Chien , H. zhuxiensis shows certain differences in having ovate, purple-spotted leaf; 10 × 3–5 mm, oblong, simple labellum; slightly involute labellum margin; upcurved labellum apex; and a significantly shorter spur compared with the ovary (Table 2 ).

Description.

Terrestrial herbs, 17–25 cm tall. Tubers ellipsoid, 4–11 × 3–5 mm. Stem slender with 1 tubular cataphyll at the base, 1 - or rarely 2 - leaved. Leaf solitary, ovate, 6–12 × 5–8 cm, apex subacute, base cordate or contracted into amplexicaul sheath, adaxially green with purple spots, rarely uniformly green, abaxially pale green. Inflorescence terminal, 14–23 cm long with 1–2 sterile bracts; laxly 4–9 - flowered; floral bracts lanceolate, to ca. 11 mm, apex acuminate or long acuminate. Flowers purplish red; pedicel and ovary straight or slightly arcuate, 13–21 mm long. Dorsal sepal ovate-elliptic, 6–9 × 3–7 mm, apex obtuse, 1 - veined; lateral sepals broadly ovate, oblique, spreading, 7–10 × 5–8 mm, 1 - veined, apex obtuse. Petals obliquely ovate, 6–7 × 4–5 mm, 1 - veined, apex obtuse, purplish red. Labellum oblong, 10 × 3–5 mm, purplish red, adaxially finely papillate, simple; margin slightly involute, irregularly crenate; apex upcurved, obtuse to emarginate; spur short and infundibuliform, slightly curved downwards, narrowly conic, 4–6 mm long, entrance 2–2.5 mm wide. Column ca. 3 mm long; rostellum tongue-like, purple, ca. 2 mm, apex rounded.

Distribution and habitat.

H. zhuxiensis is currently known to have two populations in Shibali Long Canyon National Nature Reserve, Zhuxi county, Hubei Province, China. The two populations are about 500 meters apart along the rock wall of the canyon. The new species grows on the rock wall together with H. henryi . The canyon is an arid valley, and many shrubs and mosses grow on the rock walls on both sides.

Preliminary conservation assessment.

Only two populations comprising approximately 10 mature individuals were found in Shibali Long Canyon National Nature Reserve, Zhuxi County, Hubei Province, China. The two populations are about 500 meters apart and growing on the rock wall alongside H. henryi . The habitat of H. zhuxiensis could be easily disturbed by development as it is close to roads and villages. Due to the limited population size and restricted distribution of Hemipilia zhuxiensis , the new species should be preliminarily classified as Critically Endangered ( CR B 2 ab; C 2 a (i); D) according to the guidelines of the International Union for Conservation of Nature ( IUCN) Red List Categories and Criteria ( IUCN Standards and Petitions Committee 2022).

Etymology.

The specific epithet refers to the name of the type locality in Zhuxi County.

Vernacular name.

The Chinese name is “ 竹溪舌喙兰 ”.

Phenology.

Flowering in June.

Figures

Figure 3. Hemipilia zhuxiensis A habit B flower (front view) C flower (top view) D flower (side view) E labellum and column F spur G dorsal sepal H lateral sepals I petals. Drawn by Ta-Li Cai.

Figure 4. Hemipilia zhuxiensis A habit B flower and spur (side view) C morphological contrast of H. zhuxiensis (left) and H. henryi (right) D flowering whole plant E column and labellum F tubers and roots G leaves (adaxial and abaxial view).

Figure 5. Photograph of the herbarium specimens of H. zhuxiensis Hong Liu (left) and H. henryi Rolfe (right).