Skip to main content

Rose taro (Alocasia roseus) from Aceh, Indonesia, similar to Alocasia flemingiana and Alocasia arifolia

Dlium Rose taro (Alocasia roseus) from Aceh, Indonesia, similar to Alocasia flemingiana and Alocasia arifolia

NEWS - Rose taro (Alocasia roseus Asih & Yuzammi, sp. nov.) from Aceh Besar District, Sumatra (Indonesia) was found to produce a striking inflorescence and is morphologically similar to Alocasia flemingiana Yuzammi & A.Hay and Alocasia arifolia Hallier f.

Alocasia (Schott) G.Don (Araceae Juss.) consists of 100 species, but recent studies suggest there may be 41 additional undescribed species. The genus is distributed in tropical and subtropical Asia from Malesia to Oceania and mainland Australia.

Borneo is considered to have the richest Alocasia diversity and endemism. However, the diversity and distribution of Alocasia is poorly understood in the Indonesian archipelago with about 27 known species. Prior to this study, there were 7 species recognized in Sumatra. Knowledge of Alocasia in Sumatra is inadequate.

The last taxonomic revision was conducted over 25 years ago which recognized 6 taxa of Sumatran Alocasia: Alocasia alba Schott, Alocasia arifolia, Alocasia inornata Hallier f., Alocasia longiloba Miq., Alocasia kerinciensis A.Hay, and Alocasia puber (Hassk.) Schott. Alocasia macrorrhizos (L.) G.Don is listed as an introduced species to Sumatra.

Alocasia is known as one of the most popular ornamental plants, sought after and traded by hobbyists and the general public, many species are collected directly from the forest and traded illegally.

A. roseus is only known from Aceh Besar, Sumatra Island. It grows on forest slopes, in shady and humid places. The specific epithet, roseus, is based on the pale pink staminode appendages. This appendage color is rare in this genus.

The new species is only known from a single location in the forest near Kueh Kemukiman Keude Bieng, Kueh Village, Aceh Besar District, Aceh Province, Indonesia. Because further populations may occur, the researchers chose to assess the status as Data Deficient (DD) according to the IUCN Red List criteria (2022).

The species is included in the informal group “Macrorrhizos” (sensu Hay 1998) because of the paired inflorescences, the spathe constriction parallel to the sterile cleft of the spadix and the synconent covering of the thecae. It is the second species, besides A. balgooyi, in the Macrorrhizos group that lacks a naked sinus in the posterior lobe.

A. roseus also has a different appendix color from other species in the Macrorrhizos group. The pink appendix color is a rare color and is only found in A. melo and A. princeps.

New species similar to A. flemingiana and A. arifolia, but with greyish-green adaxides and pale red to greenish-purple or pale brownish-green abaxial leaves, no veins, no glabrous sinuses and pale pink appendages (vs. medium to dark green adaxides and yellowish/paler green abaxial leaves, inconspicuous to conspicuous veins, glabrous sinuses up to 3 cm long and pale cream/apricot appendages).

DESCRIPTION

Rose taro (Alocasia roseus) is a species of plant in the Araceae (Aroideae, Colocasieae), small herb c. 55cm tall; rhizome erect; leaves several together; petiole 34–38 cm long, pale dull green, glabrous, faintly mottled greenish, sheathing in the lower about 1/3 of its length, pale dull green.

Blades leathery, sagittate, grayish green adaxially, reddish to greenish purple to pale brown greenish abaxially, margin entire; anterior lobe 12.8–14.4 cm long, 9.7–11.6 cm wide, the widest is base of anterior lobe, tip acuminate, 7 mm long.

Anterior costa with 4–5 primary lateral veins on each side, proximal ones diverging at 76–96° on each side then running to submarginal vein, distal primary veins diverging at 40–45° on each side, primary vein prominent adaxially then forward to marginal becoming flush to lamina, prominent abaxially, with inconspicuous axillary glands, secondary and tertiary venation flush to lamina adaxially, rather prominent and conspicuous abaxially then running to conspicuous submarginal vein inserted c. 1.5 mm from margin, interprimary collective veins absent.

Posterior ribs diverging at 60–80°, not naked in the sinus; posterior lobes acute, 6–7.2 cm long.

Inflorescences solitary or in pairs, subtended by green cataphylls and then dried at flower anthesis; peduncle to c. 14.6 cm long, resembling petioles in color and faintly mottled; spathe c. 9.7cm long; lower spathe ovoid, yellowish green, c. 2.3 cm long, c. 1.8 cm diam,

Limb lanceolate, yellow to greenish, erect then tilted 45° after 3 days, separated from the lower spathe by a constriction at the base of male flowers or at top sterile interstice (to the midpoint of the male zone); spadix shorter than the spathe, c. 7 cm long, shortly stipitate, 2–4 mm, whitish-green, cylindric.

Female zone cylindrical, 0.9–1 cm long, 0.9 cm wide; ovaries subglobose, green, stigma raised on a style 0.5–1 mm, conspicuously, (2–)3–4-lobed, pale yellow; sterile interstice cream-coloured, not attenuate, 0.4–0.5 cm long, narrower than male zone, with 4–5 whorls of rhomboid synandrodia;

Male zone cylindrical, cream-coloured, 1.1–1.2 cm long; synandria rhombohexagonal to somewhat irregular, with the synconnective overtopped the thecae; thecae opening by apical pores; appendix pale pink, gradually tapering to a blunt point, faintly irregularly channeled, c. 3.5–4.2 cm long, slightly wider than the male zone; fruit unknown.

Original research

Asih NPS, Erlinawati I, Yuzammi, Hadiah JT (2024). The Araceae of Sumatra I: A new species of Alocasia from Aceh, Indonesia. PhytoKeys 249: 223-229, DOI:10.3897/phytokeys.249.133737

Dlium theDlium
Labels:

Popular Posts

Tekijem (Cyperus cyperoides)

Tekijem ( Cyperus cyperoides ) is a plant species in Cyperaceae, annual grasses that grow in seasonal wetlands, open or shaded fields, swamps, ponds, rice fields, roadsides, open forests, secondary forests and shrubs at altitudes up to 1,800 m in the tropics. C. cyperoides has an upright, triangular shape, 20-75 cm tall from a very short rhizome and has no stolon. The lanceolate-shaped leaves are narrow and long, the tips are pointed, slippery, shiny, green and grow at the bottom and at the top of the stem. The terminal flower appears on the tip of the stem, cylindrical spiklet shaped and green. Each stem has two to seven flowers, each of which has a short or long stem that grows at the end of the stem together with the leaves. Tekijem grows solitary or in small groups at a distance. Propagating using vegetative and generative methods using seeds. At least three sub-species are Cyperus cyperoides cyperoides , Cyperus cyperoides flavus and Cyperus cyperoides pseudoflavus . Th...
Read more

Dry Valleys on Antarctic continent is the driest place in the world

The Sahara Desert is the largest desert in the world, rainfall is very low, only stretches of sand and rocks without rivers and plants further strengthen the view of drought. However, it turns out that the place is not the driest place in the world. Dry Valleys in Antarctica, although the continent is covered in ice, but has one part that is completely dry. Although the average rainfall in most of the Sahara Desert is less than 20 millimeters per year, there are still drier places. Dry Valleys in Antarctica is much drier where the average rainfall is 0 millimeters per year and gets the title of the driest place in the world. The valleys have so low humidity that there is almost no ice. This is the largest ice free place on the Antarctic continent. The area is surrounded by mountains that block ice from flowing into the valley. Drought is also caused by strong katabalic gusts from mountain peaks where cold air blows down the hill due to gravity. The wind has speeds of up to 322 k...
Read more

Giant golden spider (Nephila pilipes)

Kemlanding or giant golden orbweaver ( Nephila pilipes ) is an animal species in the Araneidae, a web spider with a vertical and asymmetrical mesh, sexually dimorphic with elongated females up to 20 cm in size and has a large investment in egg production and web construction, whereas males only a few millimeters. N. pilipes displays female gigantism and male dwarfism. Females usually have a body size of 30-50 mm, the cephalothorax is 15 mm long and 10 mm wide. The stomach is 30 mm long, 15 mm wide and is mostly tawny with yellow stripes. The female has black or brown, covered in thick hairs. The two rows of eyes stick out towards the back. Plastron is mostly black and brown. The legs are very long, stick-shaped with several joints, black and yellow, lacking of hairs. Males are 5-6.5 mm in size, cephalothorax is 2.5 mm long and 2 mm wide. The stomach is 4 mm long and 1.5 mm wide. The front eye is bigger than the back eye. The legs are light brown with some hair. Yellow carapace with ...
Read more