Dendrobium jinghuanum B.Q.Zheng & Y.Wang, 2020

Zheng, Bao-Qiang, Zou, Long-Hai, Wan, Xiao & Wang, Yan, 2020, Dendrobium jinghuanum, a new orchid species from Yunnan, China: evidence from both morphology and DNA, Phytotaxa 428 (1), pp. 30-42 : 40

Dendrobium jinghuanum B.Q.Zheng & Y.Wang , sp. nov. (ḆẸ石斛; Figs. 1 , 2 )

Diagnosis: This new species is morphologically similar to D. bensoniae , D. crystallinum , and D. wardianum . It differs from (1) D. bensoniae by having a flora bract with obtuse apex and distinct crystalline papillae on the surface of anther cap; (2) D. crystallinum by having a chestnut blotch on either side of lip disk, anther cap with shorter white crystalline papillae; and (3) D. wardianum by having distinct crystalline papillae on the surface of anther cap, smaller tepals with 26 × 9 mm sepals and 26 × 15 mm petals, and stems without swollen nodes.

Type:— China. Menghai (AE海), Yunnan (Ξ南): epiphytic on tree trunks in forests, 1300 m, 11th June, 2018, Zheng 001 (holotype: CAF!).

Stems erect or pendulous, cylindric, 40–60 cm, 5–7 mm in diameter, slightly fleshy, unbranched, with many nodes, internodes 2.0–3.0 cm. Leaves oblong-lanceolate, 6.5–12.5 × 1.2–2.2 cm, leathery, with several dorsiventrally raised veins, base with clasping sheath, apex long acuminate. Inflorescences several, arising from apex of old deciduous stems, 1–3-flowered; peduncle short, 4–8 mm; basal sheaths 3 or 4, 3–5 mm; floral bracts pale white, oblong, 0.7–1.0 cm, membranous, apex obtuse. Pedicel and ovary 2.0–3.0 cm. Flowers spreading, large, with many purplish red stripes; sepals and petals creamy white, upper part purplish red, lip orange, upper part purplish red, lip disk with a chestnut blotch on either side. Dorsal sepal narrowly oblong-lanceolate, ca. 26 × 9 mm, 7-veined, acuminate; lateral sepals similar in size, 7-veined, base slightly oblique, apex acuminate; mentum narrowly conic, ca. 5 × 2 mm. Petals oblong, spreading, ca. 26 × 15 mm, 9-veined, apex acute; lip suborbicular, ca. 27 mm, both surfaces densely pubescent, margin entire. Column ca. 4 mm; anther cap subconical, with densely white crystalline papillae. Capsule elongate, cylindric, ca. 6.0 × 1.7 cm.

Flowering period: —May to June.

Distribution and habitat: — Dendrobium jinghuanum is epiphytic on tree trunks in forests and known so far only from Menghai, Yunnan Province, China.

Conservation status: —Only three locations were found to contain the new species in Menghai county. Including the type locality, 28-, 20-, and 11- individuals (ramets) were found, respectively. These sites were more than 2.6 km apart from each other. Up to now, the number of the orchid’s mature individuals was found to be less than 250. Hence, the species should be preliminarily treated as Endangered (EN D) according to the World Conservation Union Red List Categories and Criteria version 3.1 ( IUCN 2000).

Etymology: —Professor Zhen-Hua Peng (1931 – 2014), was a famous Chinese forestry scientist who devoted all life to the field of forestry ecology, urban forestry, and bamboo genetic research. The specific epithet name for honoring Professor Zhen-Hua Peng is consisted of “Jing-”, the abbreviation of his hometown “Jingdezhen”, and his monicker “Hua”. The species epithet name is the combination of “Jing-” and “-Hua”.

Figures

FIGURE 1. Dendrobium jinghuanum B.Q.Zheng & Y.Wang. A. Flowering plant. B. Flower, dorsal view. C. Decomposition of a flower. D. Column with an anther cap, side view. E.Anther cap adhered to a column, dorsal view. F. Pollinarium. G.Anther cap, front view (left), dorsal view (middle), and side view (right). Photographs by Bao-Qiang Zheng & Long-Hai Zou.

FIGURE 2. Dendrobium jinghuanum B.Q.Zheng & Y.Wang. A. Ramets with vegetative and flowering stems. B. Flower, front view. C. Flower, dorsal view. D. Decomposition of a flower. E. Floral buds. F. Column with an anther cap. G. Pollinarium. Illustration based on the holotype, Zheng 001, by Jialin Shan.