Arenga undulatifolia

Arenga undulatifolia

The wavy-leaved arenga (Arenga undulatifolia Becc., 1886) is an arboreal species belonging to the Arecaceae family.

Systematics –
From a systematic point of view it belongs to:
Eukaryota domain,
Kingdom Plantae,
Magnoliophyta division,
Class Liliopsida,
Arecales Order,
Arecaceae family,
Genus Arenga,
Species A. undulatifolia.
The terms are synonyms:
– Arenga ambong Becc.;
– Saguerus undulatifolius (Becc.) Kuntze.

Etymology –
The term Arenga comes from aren(g), the Malay vernacular name of a palm belonging to this genus.
The specific undulatifolia epithet is the combination of the Latin terms undulatus, a, um, i.e. wavy and folium, i.e. leaf, in reference to the pinnulae of the leaves which have wavy edges.

Geographic Distribution and Habitat –
The Arenga undulatifolia is a palm native to Borneo, Philippines (Island of Palawan) and Indonesia (Island of Sulawesi) and present in south-east Asia: Malaysia, Indonesia, Philippines.
Its habitat is that of the primary rainforest, only rarely in areas of secondary growth, at altitudes up to 1,500 metres, where it mainly grows in calcareous soils along the banks of watercourses.

Description –
The Arenga undulatifolia is a monoecious, monocarpic, cespitose palm, which at times appears solitary, with 3-5 m tall stems, even if in cultivation they often remain lower.
Overall, the plant can reach up to 9 m in height.
The trunk is covered with a carpet of dark fiber which falls off when it is almost ripe. The fallen fiber leaves behind a smooth dark green ring scar on the trunk.
The leaves are large (up to 3 m long) with leaflets (45 – 60 cm long) widely spaced. The leaflets are wavy at the edges, dark green above and silvery below. The leaf stalk is short and thick.
The inflorescences emerge from the base of the leaves and are usually hidden by the foliage. These are branched, initially erect then pendulous, which bear either only male or only female flowers, but always on the same plant.
The male flowers have a color ranging from yellow to orange to brown, and have an intense spicy smell.
The tiny female flower is greenish white.
The fruits are globose, of 3-4 cm of diameter; they have a brown color when ripe. The pulp contains irritating substances, therefore to be handled with caution, possibly wearing gloves.
The fruits contain 3 seeds and a caustic pulp.

Cultivation –
Arenga undulatifolia is an evergreen palm that is harvested from the wild for local use as a food and source of materials. Furthermore, it should be remembered that all the species of this genus have recognized or potential ornamental value.
As far as cultivation is concerned, it is reported that the individual stems do not flower until they are ripe. From each node on the stem a flowering shoot is produced, starting at the node at the top of the plant and working down to the base. Vegetative growth ceases when the first flowering shoot is produced and the stem dies once flowers have been produced from the basal (monocarpic) node.
The multi-stemmed species usually produce new stems and therefore the plant does not die when the single stems die.
For its cultivation it is a palm that needs large spaces to bring out its characteristics to the fullest, and perhaps it is also for this reason that it is relatively uncommon outside its places of origin.
The plant can be cultivated in the tropical and humid subtropical climate zones, with minimum temperatures generally above the 16-18 °C, even if it can bear isolated drops in temperature down to 0 °C for a very short time, even if with damage to the foliage.
It is to be positioned in full sun, or in slight shade, on well drained soils, rich in organic substance.
The plant propagates by seed; from germination a deep root is formed before the seedling emerges above ground level; for this reason the seed should be sown in single and deep containers. It is recommended to pre-soak the seed for 24 hours in warm water before sowing. It can take 3 to 6 months or more before signs of growth above ground level are seen.
In general, fresh seeds germinate in 4-10 weeks at a temperature of 24-28 °C, growth is relatively fast under the best cultivation conditions.

Customs and Traditions –
Arenga undulatifolia is known by some local names such as: aren gelora, kabun jaka (in Malay).
This palm is one of the most ornamental palms, both for the large wavy leaves and for the color contrast between the whitish lower page and the dark green upper one with bluish metallic reflections that the slightest wind makes even more evident.
In the areas of origin, however, the plant has mostly food uses, while there are no known medicinal uses.
The marrow of the plant was, especially in the past, an important source of carbohydrates (sago) for some indigenous populations, especially in times of famine; this was cooked with meat and is considered a delicacy and worthy of being included in the lunches of the most important holidays or ceremonies.
The natives of the island of Palawan, in the Philippines, used the roots of this palm, used as strings for what was their most popular musical instrument.
As for the fruit, it should be remembered that, as for other species of the genus, it is poisonous and has sometimes been used in a criminal way.
The fleshy mesocarp of fruits usually contains many oxalate crystals, making the pulp inedible.
The apical shoot (known as “heart of palm”) as mentioned, however, is edible and is also used as a vegetable.
However, the consumption of large quantities of gems is not recommended since, in some species (especially Arenga tremula) they can cause toxic effects.
Furthermore, the collection of the apical shoot also leads to the death of the single stem, as it is unable to produce lateral shoots.
Among other uses it is reported that the leaves are used for straw and wickerwork.
The petioles and midribs are used to make arrows for blowguns.
The caps for blowgun darts are made from the pith of the stalk.

Method of Preparation –
The Arenga undulatifolia is a palm with great potential as an ornamental plant, however, in the places where it grows spontaneously or is cultivated it is used to supply, as mentioned, some materials or as a food plant.
The marrow is still cooked as a vegetable or in seasoning for meat; in the areas of origin it is considered a delicacy.

Guido Bissanti

Sources
– Acta Plantarum – Flora of the Italian Regions.
– Wikipedia, the free encyclopedia.
– GBIF, the Global Biodiversity Information Facility.
– Useful Tropical Plants Database.
– Conti F., Abbate G., Alessandrini A., Blasi C. (ed.), 2005. An annotated checklist of the Italian vascular flora, Palombi Editore.
– Pignatti S., 1982. Flora of Italy, Edagricole, Bologna.
– Treben M., 2000. Health from the Lord’s Pharmacy, Advice and experiences with medicinal herbs, Ennsthaler Editore.

Photo source:
– https://eol.org/pages/1136053
– https://medialib.naturalis.nl/file/id/L.1410342/format/large

Attention: The pharmaceutical applications and alimurgical uses are indicated for informational purposes only, they do not in any way represent a medical prescription; we therefore decline all responsibility for their use for curative, aesthetic or food purposes.