Cyrtosperma merkusii (Hassk.) Schott

Cyrtosperma merkusii (Hassk.) Schott

Family

Araceae

Synonyms

Cyrtosperma lasioides Griffith, Cyrtosperma edule Schott ex Seem., ('edulis'), Cyrtosperma chamissonis (Schott) Merrill.

Vernacular Names

Malaysia Geli-geli, keladi pari, birah hutan.
English Giant swamp taro, swamp taro.
Philippines Palauan (Bisaya), palau (Bisaya), galiang (Bikol).
Thailand Kli (Malay-Pattani).
Vietnam H[aj]t cong.
Melanesia Kakake (Solomon Islands).

Geographical Distributions

The origin of Cyrtosperma merkusii is not known but possibly in western Malaysia or in Melanesia (Solomon Islands). It is now distributed wild and cultivated from Peninsular Malaysia, throughout Malaysia to Oceania, but it is absent in Sulawesi, the Moluccas and main land Papua New Guinea. It has certainly been introduced in Micronesia and Polynesia and now as a major staple food on many islands. In Sumatra and Java, it is rare but quite common in Malaysia, Singapore, Brunei and the Philippines.

Description

C. merkusii is a robust to gigantic herb that can reach up to 4 m tall and grows solitarily or in clumps.

The rhizome is short and slender to tuberous and very large, cylindrical, measures up to 2 m long and measuring 0.6 m in diametre. It is sometimes spherical, weighing up to 70 kg or even more and produces few to many suckers.

The leaves are several (6-8), with arrowhead-shaped and rarely hastate. The petiole is cylindrical, measures 0.4-3 m long, measuring up to 10 cm in diametre, usually heavily to very heavily armed with stout, conical, straight or upturned spines towards the base but unarmed in some cultivated forms, with a prominent solid pulvinus at the apex and with longitudinal air ducts inside. The blade measuring 0.3-1.3 m x 0.8 m, which sometimes armed abaxially and held horizontally to vertically with the posterior lobes down. The posterior lobes are usually somewhat longer than the anterior one. The primary venation of the anterior lobe is curvinerved in small lobes to pinnate in large lobes.

The inflorescence is solitary on a peduncle which is similar but usually shorter than the petiole. The spathe is 2.5-30 cm long, thick and fleshy, very variable in size, colour and shape. It is white, yellow, green or purple and erect to deflexed to roll back. The spadix is 2-24 cm long, as long as or more than half the length of the spathe. It is sessile or with a short stalk. The flowers are bisexual and hexamerous. The ovary is unilocular, (1-)2-ovulate and with wet receptive stigma. The stamens are exserted from the tepals at male anthesis.

The fruit is a berry, reddish-orange, sessile and with 1(-2)-seeded. The seed is campylotropous, almost circular in profile to shallowly kidney-shaped, measures 5-11 mm long, brown, with about 3 raised, warty, longitudinal crests or sparsely and more or less irregularly warty and faintly crested.

Ecology / Cultivation

C. merkusii is a tropical species, occurring between latitudes 18°N (Mariana Islands) and 20°S (Cook Islands), in lowland swamp forests, open swamps or in man-made swamp pits. It requires high temperatures, and suffers chilling injury and does not tolerate temperatures below 4°C. It mostly grows at sea level in swamps, but can be grown under year-round high rainfall as a rain fed crop up to 150 m altitude. The ideal growing conditions are natural swamp lands rich in humus, measuring about 0.5-2 m deep with slow-flowing irrigation water. C. merkusii is a very hardy plant, tolerating or withstanding drought (on atolls often because of the porosity of the soil), salt seawater sprays, brackish water and hurricanes or storms much better than most other aroid crops.

Line Drawing / Photograph

Cyrtosperma_merkusii

References

  1. Plant Resources of South-East Asia No. 9: Plants yielding non-seed carbohydrates.