Tuesday, November 26, 2024

[Botany • 2024] Alocasia roseus • A New Species of Alocasia from Aceh, Indonesia [The Araceae of Sumatra I]

 

Alocasia roseus   Asih & Yuzammi,

in Asih, Erlinawati, Yuzammi et Hadiah, 2024. 

Abstract
Alocasia roseus is described as a new species from Aceh Besar Regency, Sumatra (Indonesia). The plants found produce stunning inflorescence, leading to over-collecting in the wild. The new species is morphologically similar to A. flemingiana but differs by its greyish green adaxial leaves and pale reddish to greenish purple or pale brownish green abaxial leaves, lacking interprimary veins and sinus not naked, thecae overtopped by synconnective, and a pale pink appendix. The new species is also similar to A. arifolia, from which it differs by the glabrous and pale dull green petiole, the colour of abaxial and adaxial leaves, not forming interprimary vein, sinus not naked, and pale pink appendix. The new species is compared with other similar Indonesian taxa and an identification key to the species of Alocasia in Sumatra, supplemented with photographs, are provided.

Key words: Aceh Besar, Alocasia roseus, Indonesian flora, new taxon

Alocasia roseus: A habit B adaxial leaf C abaxial leaf D petiole E inflorescence with spathe F inflorescence with the spathe removed showing the zonation of reproductive organs G female zone (♀) H sterile interstice zone (s) I male zone (♂) J appendix (a).
 (Photographed and edited by Ni Putu Sri Asih and Julisasi Tri Hadiah).

 Alocasia roseus Asih & Yuzammi, sp. nov.
 
Diagnosis: (Table 1). Alocasia roseus is morphologically similar to A. flemingiana and A. arifolia from which it differs by having greyish green adaxial leaves and pale reddish to greenish purple or pale brownish green abaxial leaves, interprimary vein absent, sinus not naked, and pale pink appendix (vs. mid-green to dark green adaxial and green-yellowish/paler abaxial leaves, forming poorly to conspicuous interprimary vein, sinus naked up to 3 cm, and cream/pale apricot appendix).

Distribution and habitat: The species is only known from Aceh Besar, Sumatra Island. It grows on the hillside of the forest, in shade and humid areas.

Etymology: The specific epithet, roseus, is based on the pale pink appendix of the staminodes found in this new species. This color of the appendix is rarely found in the genus.


Ni Putu Sri Asih, Ina Erlinawati, Yuzammi and Julisasi Tri Hadiah. 2024. The Araceae of Sumatra I: A New Species of Alocasia from Aceh, Indonesia. PhytoKeys. 249: 223-229. DOI: doi.org/10.3897/phytokeys.249.133737