Pandanus (PROSEA Fruits and nuts)
- Protologue: J. Voy. South Seas: 46 (1773).
- Family: Pandanaceae
- Chromosome number: x= 30
Major species and synonyms
Pandanus brosimos Merr. & Perry, Journ. Arn. Arb. 21: 171 (1940).
Pandanus conoideus Lamk, Encycl.1: 372 (1785) excl. var. B,
- P. butyrophorus Kurz (1869).
Pandanus leram Jones ex Fontana, J. Asiat. Res. 3: 163 (1792),
- P. mellori Roxb. (1814),
- Roussinia indica Gaudich. (1843),
- P. fosbergii St John (1961).
- pandanus, pandan, screwpine (En)
- South-East Asia: pandan.
P. brosimos :
- Papua New Guinea: karuka (Pidgin). There are numerous cultivar names.
P. conoideus :
- Indonesia: pandan seran (Moluccas), saun (Seram), sihu (Halmahera)
- Papua New Guinea: marita (Pidgin).
P. leram :
- Nicobar breadfruit (En)
- Indonesia: pandan wong (Sundanese).
Origin and geographic distribution
The genus Pandanus, with about 600 species, is found from West Africa eastward to Madagascar, the Indian Ocean islands, India and most of warmer South-East Asia, throughout Malesia into the Pacific where it reaches the northern outpost of Hawaii, the eastern and southern outposts of Pitcairn and Henderson Islands. Many endemic species exist. Pandanus cultivars are primarily non-commercial or tribal and village plants, though they may enter the economy at a very local level. In some localities pandan cultivars are old components of traditional agriculture. The cultivars of Pandanus form several distinct groups based on different species or species-complexes. P. brosimos occurs in the New Guinea highlands, mostly cultivated or retained in cleared forest. P. conoideus is a New Guinea-Moluccan crop and is unknown elsewhere in Malesia and the Pacific. P. leram is primarily a species of the Nicobar, Andaman and Maldive Islands, but is also found sparsely in Java and Sumatra.
Pandans provide two major categories of useful materials: food products and textile fibres. For the most part these are based on different species. Relevant here are the categories with edible flesh (pericarp) and with edible seeds.
- Edible flesh (pericarp). This category encompasses two quite different groups of pandans: species with oily pericarp, and those with pericarp mainly consisting of carbohydrates. The first group consists chiefly of P. conoideus, with a few rather dubious related species (P. englerianus Martelli, P. magnificus Martelli). They are confined to Melanesia, primarily to New Guinea, but also extend slightly west into the Moluccas. They are generally known as "marita". The edible pericarp is mostly red (or yellow in some forms) and noticeably oily. The second group consists mainly of P. tectorius Parkinson, from which the principal edible species P. fischerianus Martelli has developed; the latter is cultivated but not found in Malesia. P. leram also belongs to this group. The wild forms of P. tectorius can be used by cooking and straining the pericarp of the ripe fruits, but are scarcely sweet. They contain large amounts of calcium-oxalate crystals (raphides and rhomboids) which irritate the mouth unless broken down by heating. In the better cultivars in Micronesia, the carbohydrate content includes a fair amount of sugar, and the raphides content is much reduced so that the fruit can even be eaten raw in some forms. Amongst aboriginal tribes some other pandans may be used occasionally for their edible pericarp; such usage is reported for P. houlettei Ridley in Peninsular Malaysia. The ripe fruits often have a strong fragrance somewhat resembling overripe pineapple.
- Edible seeds. The premier species for edible seeds is the "karuka" of New Guinea; the name applies to P. brosimos and the very closely related P. julianettii Martelli. The seeds are oily and contain a fair amount of protein. They might be considered equivalent to coconuts in their use and value. P. dubius Sprengel also has edible seeds. Presumably usage is limited to natural stands. Probably all species of Pandanus produce edible seeds; the thickness and remarkable density of the endocarp inhibits their use.
The commercial uses of pandans appear to be largely limited to textiles made from leaf fibres (P. dubius, P. kaida Kurz, P. odoratissimus L.f., P. tectorius), the various products such as bags, hats, pocketbooks, mats etc. being marketed mostly by villages or tourist shops. Perfume and beverages from the staminate inflorescences of P. odoratissimus are produced industrially in India. In New Guinea karuka and marita fruits are traded chiefly by barter, but occasionally for cash.
Pericarp flesh of P. tectorius contains per 100 g edible portion: water 80 g, protein 0.4 g, fat 0.3 g, carbohydrates 19 g, fibre 0.3 g. No data are available for marita. Oven-dried seeds of karuka (P. brosimos) contain per 100 g edible portion: water 6-10 g, protein 8.5-14 g, fat 0.4-37 g, fibre 5-12 g, the remainder consisting of ash and carbohydrates.
- Evergreen, woody plants with an erect to decumbent stem, usually forming rigid prop roots from (defoliated) leaf axils; often branched in a trichotomous or dichotomous pattern; stems often knobbly or prickly, with manifest leaf scars; bark thin, often green just below the epidermis.
- Leaves spiralled in three series, linear and undivided, usually M-shaped in cross-section, usually with prickles along the margins and the underside of the midrib; in some species leaf apex on the upper surface with two sharp pleats, one each side of the midrib, these pleats sometimes prickly (prickles present or absent on strict species basis); longitudinal veins numerous, parallel; leaves often somewhat pale, sometimes very glaucous beneath; sometimes variegated with achlorophyllous bands (mutant forms often perpetuated as horticultural forms); some mutant forms with unarmed leaves.
- Plants strictly unisexual.
- Staminate inflorescences ephemeral, bracteate, usually spicate; spikes consisting of perianthless flowers, each flower a cluster of stamens; pollen mostly white to yellowish, often scented; staminate bracts mostly white to cream or yellow, sometimes orange to purplish; inflorescence depleted of pollen and decaying within 3-4 days.
- Pistillate inflorescence either a globose to cylindric head, or a spike of such heads; upper bracts early caducous; each head consisting of either massed unilocular carpels ripening as drupes or of 2 to many-celled massed carpels (the stone of each ripened carpel containing 2 to many seed chambers); styles none; stigmas always distinct on the apex of each carpel.
- Fruit syncarpous, ripening to yellow, orange, red, or occasionally purplish-red, the exocarp of each carpel firm to fleshy; mesocarp toward the base always fibrous; endocarp bony.
- Seeds endospermous, always retained within the thin to massively thick bony endocarp.
P. brosimos :
- Erect tree, sparsely branched above; trunks with fairly short basal prop roots.
- Leaves large to very large, thickly leathery, commonly about 3-4 m long and 8-12 cm wide, broadly linear and attenuate at apex; leaf apex upper surface with the twin pleats bearing a few prickles (only in juvenile leaves and seedling leaves; unarmed in mature leaves of adult trees).
- Staminate inflorescence a large branched spadix bearing about 12 elongate cylindric spikes, these composed of numerous staminate phalanges; each phalange with a column about 3 mm long, and about 6-9 subsessile elongate anthers borne around apex of column, often with a few sterile staminodia.
- Pistillate inflorescence a solitary, subglobose to ovoid or ellipsoid head, subtended by whitish to cream bracts, and composed of numerous fairly slender 1-celled carpels, ripening as drupes. Stigma rather large, oblique or vertical, reniform to V-shaped. Endocarp comparatively thin; endosperm copious. (This description applies almost fully also to P. julianetti.)
P. conoideus :
- A branching, arborescent shrub to 4-7 m tall; prop roots prickly.
- Leaves commonly 1-2 m long, often 5-8 cm wide, often somewhat glaucous beneath, thin to firm, but not rigid, apex acute, not apiculate; margins and midrib prickly.
- Inflorescence: staminate inflorescences are not known; pistillate head oblong-cylindrical, enveloped closely in yellowish bracts; stigma flat, blackish, rather broad.
- Fruit head when ripe often 30-40 cm long, composed of densely packed, very numerous, small unilocular drupes with red (rarely yellow) oily pericarp; endocarp small, comparatively thin.
P. leram :
- A large branched tree with elongate basal prop roots.
- Leaves large to massive, up to 5 m long and 10-15 cm wide; apex attenuate-acute; margins and midrib prickly.
- Inflorescence bracts cream; staminate inflorescence a massive branched spadix; spikes oblong, composed of numerous phalanges, these of about 20 stamens arranged umbellately on a stout column 6-7 mm long; anthers apiculate; apiculations minutely tufted at the apex; pistillate inflorescence a solitary, globose head composed of several-celled massed carpels; in fruit, massed carpels very large, often 12-15 cm long; stigmas large, corky; pericarp yellow to orange.
Growth and development
Pandans are usually grown from stem cuttings. Growth is often very rapid, with establishment of a modest trunk (20-30 cm) and a rosette of large leaves in 3 years. Seed germination is often very slow. Seedlings tend to produce erect trunks, while plants grown from cuttings may be permanently decumbent. The latter bear 2-3 years earlier than trees raised from seed. Fruiting in some species may occur in the 4th or 5th year, but in others (e.g. karuka) usually 1 or 2 years later. Fruiting is often biennial in karuka, and may be sporadic in other species.
Parthenocarpy is the rule, and apomixis is a common phenomenon. In several species, e.g. P. tectorius, P. odoratissimus and P. dubius, pistillate trees grown far from their native populations produce viable seed, which must obviously be apomictic.
Other botanical information
The P. brosimos - julianettii complex is subject to experimental verification in which P. iwen Stone and P. carrii St John should also be taken into account. Perhaps P. julianettii is a cultigen of P. brosimos; it is always cultivated and found mostly between 2000-2500 m; its leaves are usually green beneath, its drupes 9-12 cm long, rather rounded at the apex. P. brosimos often grows wild above 2500 m altitude, its leaves are usually very bluish-glaucous beneath and its drupes are 6-8 cm long, rather acute at the apex.
Species related to P. conoideus are P. hollrungii Warb. and P. cominsii Hemsley. They are wild plants but may be used in the same way as the preferred true maritas. The unrelated species P. beccarii Solms and others related to it, may occasionally also be used like P. conoideus, but their drupe pericarps are less oily and are probably regarded as poor substitutes.
It has been customary to ascribe the principal littoral Pandanus and cultivated screwpine of the region to a single species, either P. tectorius or P. odoratissimus (by some considered identical). The best edible kinds of the Pacific are sometimes included under var. pulposus Martelli. Some authors claim that many local endemic littoral species occur, a claim largely refuted by the evidence.
Reference should be made to natural habitats since growing conditions under cultivation vary. Karuka (mainly P. brosimos) grows only at higher altitudes, flourishing in the New Guinea highlands between 2000 and 3300 m and rarely seen below about 2000 m. Originally components of the upper montane vegetation, the trees are in the first instance simply retained while forest is cleared. Later, they are propagated vegetatively or by seed. Marita (mainly P. conoideus) are chiefly lowland plants but have been found up to 2000 m altitude. They scarcely overlap the altitudinal zone of karuka. Some clones of P. odoratissimus and P. tectorius are especially well-adapted to maritime, sandy habitats, but none do well at upper altitudes or in heavy, poorly-drained loam soils.
Propagation and planting
Suckers, when available, are an excellent clonal means of reproduction. Cleanly removed from the leaf axils, they can be planted straight away or rooted first in a sandy medium. Using stem cuttings or full-sized stems is another method favoured in Micronesia. Stems with slightly developed aerial roots are cut, the leaf crown trimmed but not cut off, and the cuttings inserted obliquely in the medium. Seedlings develop more rapidly from previously weathered drupes or syncarps. This suggests that removal of pericarp and perhaps scarification of the outer endocarp could accelerate germination. Germination may take several months or perhaps a year for some species.
Karuka can be propagated either vegetatively or by seed. Marita are normally propagated by cuttings because fruits are generally seedless.
Pandans are not usually grown in regularly spaced stands. Domestic plantings tend to consist of a few plants intermixed with other species. In the New Guinea highlands, a household may have 1-2 karuka trees nearby, but it "owns" trees scattered at often considerable distances. A typical Malaysian village house may have perhaps a dozen small plants of P. amaryllifolius Roxb. ("pandan wangi"), a few clumps of P. kaida ("mengkuang"), a single decorative plant of one of the variegated pandans, and if near the sea, some possibly wild or semi-wild clumps of P. tectorius or P. odoratissimus ("pandan laut").
Diseases and pests
Remarkably few diseases and pests afflict pandans and these seem most evident amongst cultivated plants and least among wild ones. Fungal diseases or predation by large insects may lead to early leaf fall. Leaf miners (hispine beetle larvae and certain moth larvae) do some damage, and occasionally large beetle larvae which consume the seed may be encountered in the endocarp chamber.
Handling after harvest
Marita fruit is boiled and the seeds (stones), fibres and core filtered out to leave a mushy paste of an oily texture with scarcely any taste. This is used as a sort of butter for starchy foods, especially sweet potato. A similar mush is prepared from fruits of the better types of P. tectorius in Micronesia and Polynesia.
Karuka fruits, if not consumed immediately after harvest, are slowly desiccated and stored (up to 2 years for properly dried fruit).
Genetic resources and breeding
When forest is cleared, staminate karuka plants are usually destroyed because they are not considered useful. Hence, conservation of staminate plants is becoming necessary with a view to future breeding programmes.
As a component of subsistence agriculture, pandans apparently are of only marginal interest to agricultural institutions; even information on yield levels is lacking. Although they are indeed minor crops grown for domestic use, local markets and the tourist trade, they are often of considerable importance within a village or tribe. Ingenuity in developing new uses for pandan fruits and seeds, as well as pandan textiles and pandan flavourings, could enhance their value.
Where vegetation is impoverished, the ecological properties of pandans can be used to advantage, e.g. in rapidly stabilizing beaches with hardy shrubs, hedging wetland fields, landscaping public areas and wastelands, enhancing gardens with their prominent silhouettes.
The karuka seems poised to become a New Guinea-wide crop grown throughout the highlands above 2000 m and valuable enough to deserve the attention of agricultural research workers. Possibly karuka seeds could be promoted as a specialty export.
- Hyndman, D.C., 1984. Ethnobotany of the Wopkaimin Pandanus: significant Papua New Guinea plant resource. Economic Botany 38: 287-303.
- Lee, M.A.B., 1987. Seed and seedling production in Pandanus tectorius. Biotropica 21: 57-60.
- Miller, C., Murai, M. & Pen, F., 1956. The use of Pandanus fruit as food in Micronesia. Pacific Science 10: 3-16.
- Stone, B.C., 1967. Studies of Malesian Pandanaceae, 1. Gardens' Bulletin Singapore 22: 231-257.
- Stone, B.C., 1975. On the biogeography of Pandanus (Pandanaceae). Comptes Rendus de la Société de Biogéographie (Paris), Séance 458: 1-22.
- Stone, B.C., 1982. New Guinea Pandanaceae: First approach to ecology and biogeography. In: Gressit, J. (Editor): Ecology and Biogeography in New Guinea. The Hague. Monographiae Biologicae 42. pp. 401-436.