Friday, April 24, 2020

[Botany • 2019] Conamomum odorum (Zingiberaceae) • A New Species from central Vietnam

Conamomum odorum Luu, H. D. Tran & G. Tran

in Luu, Tran, ... et Tran, 2019. 
Sa nhân thơm  ||  DOI: 10.15625/0866-7160/v41n3.13671 
Photos: Luu Hong Truong

Conamomum odorum is described as a new species from Khanh Hoa Province, Central Vietnam. It is characterized by sweet smell, striate and narrowly elliptic leaf leaves with short petiole and ligule, ovoid congested inflorescence, pubescent calyx, cream corolla lobes, yellow, obovate and reflexed labellum with median red bands at base and hairy ovary. The new species is illustrated with detailed photographs of key characters and morphologically compared to its closest congeners C. piereanum and C. rubidum. A distribution map of the genus in Vietnam is provided.

Keywords: Conamomum odorum, fragrant, new species, Vietnam, Zingiberaceae.

Figure 2.  Conamomum odorum.
A. Habit. B. Rhizome and inflorescences. C. Ligule. D. Inflorescence. E. Flower dissection. F. Ovary with epigynous glands and anthers (side and front views)
[Photos: Luu Hong Truong]

 Conamomum odorum Luu, H. D. Tran & G. Tran, sp. n.

 Morphologically closest to Conamomum rubidum in having yellow flowers, radical inflorescence and 3-lobed labellum with reflexed margins, but differs by smaller laminas (25–30 × 3–3.5 cm), shorter petiole (2–4 mm), ovoid inflorescence, fully pubescent bracts, pubescent calyx, cream corolla lobes, slightly 3-lobed and obovate labellum, hairy ovary and longer filament (ca. 13 mm) (vs. 30–45 × 4.5–7 cm laminas, 5–9 mm petiole, obovoid inflorescence, basally pubescent bracts, glabrous calyx, reddish corolla lobes, strongly 3-lobed and reniform labellum, glabrous ovary and 7–8 mm long filament).

Etymology The specific epithet refers to the special fragrance of the whole plant. After the specimens are dried, the odor becomes stronger and lasts for several years in the herbarium specimens. 

Proposed Vietnamese name: Sa nhân thơm. 

Notes: The new taxon is morphologically closest to C. rubidum as they share the following characters: radical congested inflorescence, yellow and 3-lobed labellum with reflexed margins. However, they can be distinguished by key morphological differences as shown in the diagnosis and table 1. The shape and color of the labellum in C. odorum may recall those in C. pierreanum Gagnep. from Cambodia (de Boer, 2018; Gagnepain, 1906 & 1908; Lamxay & Newman, 2012) but both species have many different morphological characters (table 1) that make them distinct from each other.

Luu Hong Truong, Tran Huu Dang, Nguyen Quoc Dat, Nguyen Tran Quoc Trung and Tran Gioi. 2019. Conamomum odorum, A New Species of Zingiberaceae from central Vietnam. ACADEMIA JOURNAL OF BIOLOGY. 41(3); 41(3): 55–59. DOI: 10.15625/0866-7160/v41n3.13671