Cylindrolobus motuoensis X.H.Jin & J.D.Ya, 2019

Ya, Ji-Dong, Jin, Xiao-Hua & Liu, Cheng, 2019, Two new species of Cylindrolobus (Orchidaceae) from the eastern Himalayas, PhytoKeys 130, pp. 107-113 : 107

Cylindrolobus motuoensis X.H.Jin & J.D.Ya sp. nov. Figures 1 , 3A

Diagnosis.

Cylindrolobus motuoensis is similar to C. gloensis (Ormerod & Agrawala) Schuit., Y.P. Ng & H.A. Pedersen, and C. foetidus (Aver.) Schuit., Y.P. Ng & H.A. Pedersen in terms of morphological structure and shape of the flowers ( Hu et al. 2010, Agrawala and Ormerod 2014, Ng et al. 2018). The new species can be distinguished from C. gloensis by the smaller flowers, elliptic and concave bracts, and ovate lip with three keels, mid-lobe thickened and papillate on margin. The new species can be distinguished from C. foetidus with longer and wider leaves, dark red and elliptic floral bracts, white flowers and falcate-lanceolate lateral sepals.

Type.

CHINA. Xizang Autonomous Region: Motuo, subtropical evergreen broad-leaved forest, alt. 2000 m, 26 Feb 2017, Ji-Dong Ya, Cheng Liu, Hua-Jie He 17HT0073 (holotype: KUN!).

Additional specimen examined.

CHINA. Xizang Autonomous Region: Motuo, subtropical, evergreen broad-leaved forest, 26 Feb 2017, Xiao-Hua Jin, Ji-Dong Ya, 17HT1088 (paratype: KUN!)

Description.

Epiphytic herb. Roots terete, slender, pubescent, ca. 1.0-1.5mm thick. Rhizome creeping, to 3-4 mm thick. Stem terete, slender, 3(2) leaved apically, covered by close-fitting sheaths, 18-24 cm long, 3-6 mm thick. Leaves ligulate-lanceolate, acuminate, 10-13 cm long, 1.5-2.0 cm wide. Inflorescences axillary, pubescent, borne on near the apical of the stem, 2-3 cm long, 2 flowered; peduncle 1.0-1.5 cm long; 2 sterile bracts, smaller, amplexicaul; rachis 0.2 cm long, floral bracts dark red, elliptic, acute, concave, sparsely tomentum, 7 mm long, 3 mm wide. Flowers white, sepal externally with brown tomentum, peduncle and ovary ca. 1.0-1.5 cm long, densely brown tomentum. Dorsal sepal lanceolate, acute, 5 veined, 11 mm long, 4 mm wide; lateral sepals falcate-lanceolate, acute, 5 veined, 9 mm long, 5 mm wide, base adnate to column foot form a subglobose and obtuse mentum; petals lanceolate, slightly oblique, acute, 3 veined, 10 mm long, 3 mm wide; labellum ovate in outline, 3-lobed, base hinged to the apex of the column foot, apex obtuse and emarginate, curved, c. 6 mm long, 3 mm wide; lateral lobes suberect, subovate, apex slightly introvert; mid-lobe ligulate, ca. 3 × 3 mm, thickened and papillate on margin, apex emarginate; disk with 3 keels, central keel longitudinal thickened, with orange papilla, running from base to the tip of mid-lobe, lateral keels glabrous, running from base to middle of mid-lobe. Column semiterete, ca. 4 mm long, broad winged at ventrally; foot incurved, ca. 3.5 mm. Anther cap ovate, ca. 1 mm × 1 mm, pollinia 8, yellowish white, compressed rectangular, anterior ca. 0.5 mm × 0.4 mm × 0.2 mm, posterior 4 smaller. Fl. February-March.

Etymology.

The new species is named after Motuo, Xizang Autonomous Region of China, where it was discovered in a subtropical evergreen broad-leaved forest.

Vernacular name.

Mo Tuo Zhu Lan (墨脱柱兰).

Figures

Figure 1. Cylindrolobus motuoensis X. H. Jin & J. D. Ya. A Plant B Inflorescence C lateral view of flower D ventral view of flower E front view of flower F adaxial sepals and petals G abaxial sepals and petals H lateral view of column and lip I lateral view of column J front view of column K front view of labellum L lateral view of labellum (rip cutting) M adaxial bract N abaxial bract O polar view of pollinarium P ventral view of pollinarium Q lateral view of pollinarium R adaxial anther cap S abaxial anther cap (Photographed by J. - D. Ya).

Figure 3. Holotype. A Cylindrolobus motuoensis X. H. Jin & J. D. Ya. B Cylindrolobus glabriflorus X. H. Jin & J. D. Ya.