Cymbidium purpureisepalum M.J.Zhu & S.R.Lan

Zhu, Meng-Jia, Ke, Shijie, Zhao, Xuewei, Wang, Qian-Qian, Chen, Guizhen, Liu, Zhong- Jian & Lan, Siren, 2022, Cymbidium purpureisepalum (Orchidaceae; Epidendroideae), a new species from China: evidence from morphological and molecular data, Phytotaxa 538 (3), pp. 225-233 : 228-231

Cymbidium purpureisepalum M.J.Zhu & S.R.Lan (紫萼兰) ( Figs 2 , 3 )

Type:— CHINA. Yunnan Province: Wenshan, 1200 m, slopes with well-drained soil, woodland, 25 November 2020, Zhu F001 (holotype: FAFU!) .

This new species is similar to C. serratum and C. tortisepalum but differs in having sepals with a purple midvein, winged toward apex with a narrowly winged mucro protruding from apex and petals with dark purple spots.

Terrestrial. Pseudobulbs produced biennially, ovoid, 2–3 × 2–3 cm, enclosed in persistent leaf bases. Leaves usually 7–11, distichous, lorate, arching, 35.0–65.0 cm × 0.8–1.3 cm, apex acute, toward the base slightly distichousequitant with membranous margins 0.1–0.2 cm wide, articulated 2.0–3.0 cm from the base. Scape arising from the base of the pseudobulb, erect, 25–30 cm long; peduncle with 6–7 sheaths 2–6 cm long; inflorescence with 3–5 flowers; floral bracts linear-lanceolate, 3–4 cm long, as same as the length of the pedicellate ovary; pedicel and ovary 3–4 cm long; sepals and petals purplish red, with a purple midvein; petals with dark purple spots; lip white, with purple sidelobes and purple spots or patches on the midlobe; sepals oblong-lanceolate, 3.5–3.8 × 0.6 cm, dorsally slightly carinate, but winged toward apex, with a narrowly winged mucro protruding from the apex; petals narrowly ovate, 2.8–3.0 × 0.8–1.0 cm, apex acuminate; lip oblong in outline, 2.2–2.5 × 0.9–1.1 cm long, trilobed; sidelobes oblong, 1.2–1.4 × 0.3–0.5 cm, minutely papillate adaxially; midlobe broadly ovate, strongly recurved, 1.2–1.4 × 1.1–1.2 cm, crenulate; disc with 2 longitudinal lamellae extending from its base to near the base of the midlobe and inflated near their apices; column 1.3–1.5 cm long, slightly arcuate, narrowly winged; pollinia 4, in 2 pairs.

Etymology: —Referring to a flower with purple sepals, from the Latin purpureus (purple) and the Greek sepalum (sepal).

Phenology: —Flowering November–December.

Distribution: —Wenshan County, Yunnan Province, China.

Habitat: —Slopes with well-drained soil, in woodland up to 1200 m.

Notes: —Inflorescence, flower and pollinaria structure are taxonomically informative and have always been characterised in Cymbidium ( Freudenstein & Rasmussen 1999, Singer et al. 2008). There are three subgenera of Cymbidium , of which C. subgen. Jensoa is terrestrial, usually with erect inflorescence, flowers of diverse colours, pseudobulbs present and typically ovoid or sometimes rhizomes underground with non-articulate leaves and four pollinia ( Liu et al. 2006). In morphology, the new species is consistent with the other species of C. subgen. Jensoa ( Liu et al. 2006) ; both have erect inflorescence and four pollinia in two pairs, but differ for its sepals with a mucro and petals with dark purple spots. The phylogenetic relationships based on the combined and nuclear DNA datasets showed that C. purpureisepalum is a member of C. subgen. Jensoa , sister to C. tortisepalum and C. serratum ( Fig. 1 ), although the position in the plastid tree is not the same. In summary, C. purpureisepalum is clearly a new species.

Figures

FIGURE 1. Phylogenetic relationships of C. purpureisepalum based on combined plastid and nuclear data. The three numbers near the nodes are Bayesian posterior probabilities (PP), maximum likelihood bootstrap percentages (BP) and maximum parimony bootstrap ML percentages (BP). “-” indicates that the node is incongruent between the topology of the Bayesian tree and the MP/ML trees. MP

FIGURE 2. Phylogenetic relationships of C. purpureisepalum based on the plastid DNA (matK) data.The three numbers near the nodes are Bayesian posterior probabilities (PP), maximum likelihood bootstrap percentages (BP ML) and maximum parimony bootstrap percentages (BP MP). “-” indicates that the node is incongruent between the topology of the Bayesian tree and the MP/ML trees.

FIGURE 3. Phylogenetic relationships of C. purpureisepalum based on nuclear DNA data (nrITS). The three numbers near the nodes are Bayesian posterior probabilities (PP), maximum likelihood bootstrap percentages (BP ML) and maximum parimony bootstrap percentages (BP ). “-” indicates that the node is incongruent between the topology of the Bayesian tree and the MP/ML trees.