Monday, December 26, 2016

[Botany • 2016] Areca jokowi • A New Species of Betel Nut Palm (Arecaceae) from Western New Guinea

Areca jokowi Heatubun

Pinang Jokowi  |  DOI:  10.11646/phytotaxa.288.2.8 

A new species of betel nut palm, Areca jokowi, is described and illustrated here. This is the third species of Areca to have been described recently from New Guinea that is closely related to the widespread, economically important species A. catechu, the cultivated betel nut palm. A discussion of its morphological characters, distribution, ecology, habitat, uses and conservation status is provided, as well as a new identification key for western New Guinean Areca.

Key words: Arecaceae, Palmae, palms, New Guinea, taxonomy

Taxonomic Treatment 

Areca jokowi Heatubun, sp. nov. 

Type:— CULTIVATED. Indonesia, West Papua Province. Kaimana Regency, Yamor District, Yamor Lake, Gariau (Urubika) village, 106 m elev., 06 June 2015, Heatubun et al. 1252 (holotype MAN!, isotype BO!, K!) 

FIGURE 2. Areca jokowi Heatubun.
A. Slender habit with irregular crown shape. B. Leaf and inflorescence held by Christian Anggua for scale. C. Inflorescence-a strongly divaricate panicle with crowded rachillae. D. Pistillate flowers, striking in their white colour. E. Close up of pistillate flower at anthesis showing stigma. F. Young fruit in section. 

A–E photos were taken from the holotype specimen (Heatubun et al. 1252), F from voucher collected by Ekspedisi NKRI Koridor Papua Barat 2016. Photos: A, F (Lt. Ardiansyah), B–E (Charlie D. Heatubun). 

Diagnosis:— This new species is similar to Areca catechu L., Areca mandacanii Heatubun and Areca unipa Heatubun in habit and inflorescence structure, but differs by the inflorescence branched to four orders, the rachillae crowded, borne very close together and not expanding widely, sinuous especially in the distal two thirds, the floral clusters uniseriate in arrangement (although distichous near the tip of the rachilla), complete floral triads (comprising two staminate and one pistillate flower) always solitary at the base of rachillae, but absent from many rachillae, the remaining floral clusters consisting of dyads of staminate flowers, or solitary staminate flowers near the rachilla tip, and the pistillate flowers with striking white calyx at anthesis. Solitary, slender palm to 15 m. Stem 7–8 cm diam.; internodes 30–34 cm. Leaves 9 in 

Distribution:— Known only from two individuals palms cultivated in Gariau (Urubika) village, on the SW shore of Yamor Lake in Yamor District, Kaimana Regency, West Papua Province, Indonesia. These palm were grown from the seeds brought from hill forest at Kepala Air Kali Ima (headwaters of Ima river) in Gunung Daweri (Mt. Daweri), near Kewo village on the border of Nabire Regency of Papua Province.

 Habitat:— Based on information gathered from the person who brought the seeds and planted this betel nut palm, the species grows in hill forest at an elevation of about 300 m altitude on soils derived from sandstones.

 Local names:— Siaku’ (Yamor dialect, Kamoro language).

 Uses:— The fruits are chewed as a betel nut substitute. However, the palm has potential as an ornamental.

Etymology:— The specific epithet refers to the acronym the President of Republic Indonesia, His Excellency Joko Widodo-Jokowi. This new species is dedicated to Mr. Joko Widodo for his exemplary leadership, his simplicity, and more importantly for his concern for the development of Tanah Papua (the Indonesian Provinces of Papua and West Papua). The common name “Pinang Jokowi” is suggested here.

  Charlie D. Heatubun. 2016. Areca jokowi: A New Species of Betel Nut Palm (Arecaceae) from Western New Guinea.  Phytotaxa. 288(2); 175-180. DOI:  10.11646/phytotaxa.288.2.8