Thatch screwpine

"Ketaki" redirects here. For the Indian tree also known as ketaki, see Pandanus odorifer.

Thatch screwpine
Growing in the mountains of Oʻahu, Hawaii
Conservation status
Least Concern  (IUCN 3.1)
Scientific classification
Kingdom:	Plantae
Clade:	Angiosperms
Clade:	Monocots
Order:	Pandanales
Family:	Pandanaceae
Genus:	Pandanus
Species:	P. tectorius
Binomial name
Pandanus tectorius Parkinson
Synonyms
Corypha laevis (Lour.) A.Chev. H.St.John H.St.John H.St.John H.St.John Kaneh. H.St.John Kaneh. Martelli Pandanus tectorius var. chamissonis Pandanus laticanaliculatus var. edulis (Gaudich.) Martelli Pandanus exilis Kaneh. B.C.Stone Pandanus tectorius f. convexus Pandanus latior B.C.Stone Pandanus christophersenii H.St.John H.St.John (Gaudich.) Martelli Pandanus tectorius var. drolletianus Pandanus lauensis (Martelli) B.C.Stone Pandanus exilis var. juddii H.St.John (J.W.Moore) B.C.Stone Pandanus tectorius var. fatyanion Pandanus lennei Pandanus bathys H.St.John H.St.John Pynaert Martelli Pandanus tectorius var. heronensis Pandanus licinus (H.St.John) B.C.Stone Pandanus extralittoralis H.St.John B.C.Stone Pandanus tectorius f. integrifolius Pandanus limitaris Agustika, S.Santiago & A.P.Keim Pandanus collatus H.St.John H.St.John Martelli Pandanus tectorius var. jonesii Pandanus littoralis F.Br. Pandanus eyesyes Jungh. (Martelli) B.C.Stone Pandanus tectorius var. laevis Pandanus angulosus H.St.John H.St.John Kaneh. H.L.Wendl. (Warb.) Masam. Pandanus tectorius var. littoralis Pandanus macfarlanei (Jungh.) Martelli Pandanus fahina Martelli (Gaudich.) Martelli Pandanus tectorius var. microcephalus Pandanus macrocephalus Martelli Pandanus complanatus H.St.John Kaneh. Martelli Pandanus tectorius var. novoguineensis Pandanus makateaensis Martelli Pandanus faramaa H.St.John (Martelli) B.C.Stone Pandanus tectorius var. ongor Pandanus malatensis Pandanus benignus H.St.John H.St.John Blanco (Martelli) J.W.Moore Pandanus tectorius var. pedunculatus Pandanus mangarevaensis (R.Br.) Domin Pandanus fatuhivaensis H.St.John Martelli Pandanus tectorius var. pulposus Pandanus mariaensis Warb. Pandanus cooperi H.St.John H.St.John (Sander) B.C.Stone Pandanus tectorius var. sandvicensis Pandanus marquesasensis Warb. Pandanus fatyanion H.St.John Martelli Pandanus aitutakiensis H.St.John H.St.John (Martelli) H.St.John (Kaneh.) Hosok. H.St.John (H.St.John) B.C.Stone Pandanus tectorius var. sumbavensis Pandanus mbalawa Martelli Pandanus ferulifer H.St.John Martelli Pandanus tectorius var. taepa Pandanus meetiaensis F.Br. Pandanus coronatus H.St.John H.St.John Martelli Pandanus tectorius var. tubuaiensis Pandanus mei (Martelli) B.C.Stone Pandanus filiciatilis F.Br. F.Br. Pandanus tectorius var. upoluensis Pandanus mendanensis Pandanus bergmanii Martelli H.St.John Martelli (H.St.John) B.C.Stone Pandanus tectorius var. zollingeri Pandanus menne Martelli Pandanus fischerianus Kaneh. H.St.John Pandanus tessellatus Pandanus menziesii Martelli Pandanus coronatus f. minor Martelli Gaudich. H.St.John Pandanus tima Pandanus metius H.St.John Pandanus fischerianus f. bergmanii H.St.John H.St.John Pandanus tolotomensis Pandanus anisos F.Br. Martelli (F.Br.) B.C.Stone H.St.John Kaneh. Pandanus tongaensis Pandanus montaguei H.St.John Pandanus fischerianus var. bryanii H.St.John H.St.John Pandanus tritosphaericus Pandanus mooreaensis H.St.John Pandanus crassiaculeatus B.C.Stone H.St.John Kaneh. Pandanus tuamotensis Pandanus moschatus F.Br. Pandanus fischerianus f. bryanii Miq. F.Br. Pandanus tuamotensis var. typica Pandanus moschatus Pandanus bicurvatus H.St.John B.C.Stone Rumph. ex Voigt Martelli Pandanus tupaiensis Pandanus motuensis H.St.John Pandanus fischerianus f. compressus H.St.John Martelli Pandanus uea Pandanus nandiensis H.St.John Pandanus crassus B.C.Stone H.St.John (Martelli) Martelli Pandanus upoluensis var. angulosus Pandanus navigatorum Martelli Pandanus fischerianus var. cooperi Martelli Martelli Pandanus adscendens H.St.John H.St.John H.St.John H.St.John (Martelli) B.C.Stone B.C.Stone H.St.John Pandanus vandra Pandanus niueensis H.St.John Pandanus fischerianus var. rockii H.St.John Van Geert ex T.Moore & Mast. Pandanus variegatus Pandanus notialis Miq. Pandanus crustatus (Martelli) B.C.Stone H.St.John Mast. Pandanus virginalis Pandanus oblatiapicalis H.St.John Pandanus flintinsularis H.St.John H.St.John Pandanus viridinsularis Pandanus oblaticonvexus Pandanus blakei Martelli H.St.John H.St.John Kaneh. Pandanus wilderi Pandanus obliquus H.St.John Pandanus fragrans Kaneh. H.St.John Pandanus yunckeri Pandanus odontoides H.St.John Pandanus crustatus f. minor Gaudich. Hosok. Pandanus odoratissimus var. laevigatus Pandanus fragrans f. koidzumii Martelli Pandanus aoraiensis H.St.John Martelli (Hosok.) B.C.Stone (Warb.) Martelli Pandanus odoratissimus f. major Pandanus fragrans f. marianus Martelli Pandanus odoratissimus var. oahuensis Pandanus cylindricus B.C.Stone Martelli Pandanus odoratissimus var. parksii Pandanus fragrans f. megastigma Martelli Pandanus odoratissimus var. pyriformis Pandanus boraboraensis Kaneh. B.C.Stone Martelli Pandanus odoratissimus var. savaiensis Pandanus fragrans f. rotensis (Martelli) Martelli Pandanus odoratissimus var. setchellii Pandanus cylindricus var. sinnau (Hosok.) B.C.Stone Martelli Pandanus odoratissimus var. spurius Pandanus fragrans f. savannarum Willd. Pandanus akiakiensis H.St.John H.St.John Kaneh. B.C.Stone Martelli Pandanus okamotoi Pandanus fragrans f. tinianensis Kaneh. Pandanus onoilauensis Pandanus cymatilis B.C.Stone H.St.John Pandanus orarius Pandanus futunaensis H.St.John Pandanus otemanuensis Pandanus bothreus H.St.John H.St.John H.St.John Pandanus ovalauensis Pandanus gambierensis H.St.John Pandanus pachys Pandanus decorus H.St.John H.St.John Pandanus pakari Pandanus glomerosus H.St.John Pandanus apionops H.St.John K.Koch H.St.John Hosok. Pandanus palmyraensis Pandanus grantii H.St.John Pandanus pansus Pandanus dhaenei H.St.John H.St.John Pandanus paogo Pandanus guamensis H.St.John Pandanus papeariensis Pandanus bowenensis Pynaert Martelli Martelli Pandanus parhamii Pandanus haapaiensis H.St.John Pandanus parksii Pandanus dicheres H.St.John H.St.John Pandanus patulior Pandanus hendersonensis H.St.John Pandanus absonus H.St.John H.St.John H.St.John H.St.John H.St.John H.St.John R.Br. Pandanus pedunculatus var. insularis Pandanus heronensis B.C.Stone Pandanus pedunculatus var. malagunensis Pandanus dilatatus H.St.John B.C.Stone Pandanus pedunculatus var. rendovensis Pandanus hivaoaensis B.C.Stone Pandanus planus Pandanus brachypodus Kaneh. H.St.John H.St.John Pandanus politus Pandanus horneinsularum Martelli Pandanus ponapensis Pandanus discolor H.St.John Martelli Pandanus prismaticus Pandanus hosinoi Martelli Pandanus asauensis Kaneh. T.Moore & Mast. Kaneh. Pandanus prolixus H.St.John Pandanus hosokawae Pandanus pseudomenne Hosok. Pandanus distinctus Kaneh. Pandanus pulposus (Warb.) Martelli Pandanus houmaensis Pandanus pulposus var. cooperi Martelli Pandanus brownii Martelli H.St.John Pandanus puniceus H.St.John Pandanus hubbardii Pandanus pusillus H.St.John Pandanus divaricatus H.St.John Pandanus pyriformis (Martelli) H.St.John Pandanus humericus Pandanus radiatus Pandanus ala-kai H.St.John H.St.John H.St.John H.St.John Pandanus raiateaensis H.St.John Pandanus inarmatus Pandanus raivavaensis Martelli Pandanus divergens H.St.John Pandanus raroiaensis H.St.John Pandanus inermis Pandanus rectangulatus Kaneh. Pandanus bullii Kaneh. Roxb. Pandanus repens Miq. Pandanus inflexus Pandanus rhizophorensis H.St.John Pandanus dotyi H.St.John Pandanus rhombocarpus Kaneh. Pandanus infundibuliformis Pandanus rikiteaensis Pandanus ater Warb. H.St.John H.St.John Pandanus rimataraensis H.St.John Pandanus insularis Pandanus rockii Martelli Pandanus douglasii Kaneh. Pandanus rotensis Hosok. Pandanus interior Pandanus rotundatus Kaneh. Pandanus cacuminatus Gaudich. H.St.John Pandanus rurutuensis H.St.John Pandanus intralaevis Pandanus sabotan Blanco Pandanus drakei H.St.John Pandanus saipanensis Kaneh. Pandanus jaluitensis Pandanus salailuaensis Pandanus aequor Martelli H.St.John H.St.John H.St.John Kaneh. Pandanus saltuarius H.St.John Pandanus samoanus Pandanus javanicus (Martelli) H.St.John Pandanus samoensis Pandanus drolletianus K.Koch Warb. Pandanus sanderi Pandanus javanicus variegatus Sander Pandanus savaiensis Pandanus calostigma f. samoanus Martelli E.J.Lowe & W.Howard (Martelli) H.St.John Pandanus schizocarpus Pandanus jonesii F.Br. Pandanus scopulorum Pandanus duriocarpoides (F.Br.) H.St.John Martelli Pandanus seruaensis Pandanus kafu H.St.John Pandanus baptistii Martelli Kaneh. Martelli H.St.John Pandanus sinuvadosus Pandanus kamptos H.St.John Pandanus smithii Pandanus duriocarpus H.St.John H.St.John Pandanus spurius Pandanus katensis (Willd.) Miq. Pandanus spurius var. weteringii Pandanus carolinensis Martelli F.Br. Martelli Pandanus stradbrookeensis Pandanus koidzumii H.St.John Pandanus subaequalis Pandanus edwinii Hosok. H.St.John Pandanus subhumerosus Pandanus korrensis H.St.John Pandanus amplexus Misonne Martelli H.St.John Kaneh. H.St.John Pandanus yorkensis Pandanus volkensii H.St.John Pandanus subulorum Pandanus viri Pandanus veitchii Pandanus kraussii Martelli Pandanus vangeertii Pandanus vahitahiensis Kaneh. Pandanus suvaensis Pandanus utiyamae Pandanus elevatus H.St.John (Martelli) H.St.John Pandanus upoluensis var. minor Pandanus upoluensis Pandanus tutuilaensis Pandanus sykesii Pandanus tubuaiensis F.Br. Pandanus kusaiensis H.St.John Pandanus tuamotensis var. locularis Pandanus trukensis Pandanus trapaneus Pandanus taepa Pandanus chamissonis H.St.John Kaneh. (F.Br.) H.St.John Pandanus tomilensis Glassman Pandanus timoeensis Pandanus tahaaensis Pandanus tikeiensis Pandanus terrireginae Pandanus laculatus H.St.John Pandanus tectorius var. yorkensis Martelli Pandanus tectorius var. uapensis Pandanus tahitensis Pandanus tectorius var. timorensis Pandanus enchabiensis H.St.John Martelli Pandanus tectorius var. suringaensis Pandanus tectorius var. stradbrookensis Martelli Pandanus tahitensis var. exiguus Pandanus tectorius var. spiralis Pandanus tectorius var. savaiensis Pandanus laevis J.W.Moore Pandanus tectorius var. sanderi Pandanus tectorius f. philippinensis Pandanus tectorius var. parksii Pandanus bassus Gaudich. Kaneh. Kunth B.C.Stone Kaneh. Pandanus tectorius var. oahuensis Pandanus tectorius var. novocaledonicus Pandanus takaroaensis Pandanus tectorius var. menziesii Pandanus tectorius f. laevis Pandanus laevis H.St.John Warb. Pandanus tectorius var. laevigatus Pandanus tectorius var. javanicus Pandanus tapeinos Pandanus tectorius var. incrassatus Pandanus erythrophloeus Lour. H.St.John Pandanus tectorius var. fragrans Kaneh. Pandanus tectorius var. exiguus Pandanus taravaiensis Pandanus tectorius var. douglasii Pandanus tectorius var. cocosensis Pandanus lakatwa H.St.John Pandanus tectorius var. brongniartii Martelli Pandanus minysocephalus Pandanus Pandanus charancanus Kaneh. Kaneh. tauensis Martelli Pandanus palkilensis Pandanus pritchardiae H.St.John Pandanus sinuosus Pandanus tectorius var. acutus Pandanus tahitensis var. niueana Pandanus subradiatus Pandanus lambasaensis Kaneh. Martelli H.St.John H.St.John Pandanus tectorius var. angaurensis Pandanus pedunculatus Pandanus evexus H.St.John Kaneh. Pandanus odoratissimus var. suvaensis Pandanus odoratissimus var. laevis Pandanus navigatorum var. elbertii Pandanus tectorius var. australianus Pandanus matukuensis Pandanus longifolius Pandanus laticanaliculatus

Pandanus tectorius is a species of Pandanus (Screwpine) that is native to Malesia, Papuasia, eastern Australia, and the Pacific Islands. It grows in the coastal lowlands typically near the edge of the ocean. Common names in English include thatch screwpine, Tahitian screwpine, hala tree (pū hala in Hawaiian) and pandanus. The fruit is edible and sometimes known as hala fruit.

Description

P. tectorius is a small tree that grows upright to reach 4–14 m (13–46 ft) in height. The single trunk is slender with brown ringed bark. It is spiny, grows to 4.5–11 m (15–35 ft) in width, and forks at a height of 4–8 metres (13–26 ft). It is supported by aerial roots (prop roots) that firmly anchors the tree to the ground. Roots sometimes grow along the branch, and they grow at wide angles in proportion to the trunk.

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  Growth habit
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  Aerial roots
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  Spiny aerial roots and leaflets
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  Fruit showing phalanges

Leaves

The leaves are usually 90–150 cm (3–5 ft) in length and 5–7 cm (2–2 ³⁄₄ in) in width. They possess saw-like margins. Some varieties have spines along the edges and ribs throughout the leaves. The leaves are spirally arranged at the end of the branches.

Flowers

Male flower

Pandanus tectorius is dioecious, meaning male and female flowers are borne on separate trees, with very different male and female flowers. Male flowers are arranged in racemes and are small, fragrant, and short-lived, lasting only a single day. The flowers are grouped in 3 and gathered in large clusters surrounded by big, white bracts. these clusters are about 1 ft in length and are fragrant. Female flowers resemble pineapples.

In Hawaiʻi the male flower is called hīnano and the bracts are used for making very fine mats (moena hīnano' or ʻahu hīnano).

Fruit

The female P. tectorius trees produce a segmented, large fruit. Although not closely related, the fruit resembles a pineapple. The fruit of P. tectorius is either ovoid, ellipsoid, subglobose or globose with a diameter of 4–20 cm (1 ¹⁄₂–7 ³⁄₄ in) and a length of 8–30 cm (3 ¹⁄₄–11 ³⁄₄ in). The fruit is made up of 38–200 wedge-like phalanges, often referred to as keys or carpels, which have an outer fibrous husk and are 8 inches in length. There are roughly 40 to 80 keys in each fruit and the color of the fruit can be yellow, orange, or red with a green top. Phalanges contain two seeds on average, with a maximum of eight reported. The phalanges are buoyant, and the seeds within them can remain viable for many months while being transported by ocean currents.

Taxonomy

Pandanus tectorius was first described by Sydney Parkinson in 1774. It is an angiosperm belonging to the genus Pandanus of the family Pandanaceae.

Distribution and habitat

Pandanus tectorius grows natively from the Philippines through the Pacific Ocean to Hawaii. It is found in parts of Malesia (the Cocos (Keeling) Islands, Java, the Lesser Sunda Islands, the Maluku Islands and the Philippines), throughout Papuasia, and in most of the tropical Pacific.

Overlooking the ocean at Sawtell, Australia.

In Australia, it is native to an area from Port Macquarie in New South Wales to northern Queensland. Both the US and the Hawaiian Islands recognize only one indigenous species, P. tectorius. Its exact native range is unknown due to extensive cultivation; it may be an early Polynesian introduction to many of the more isolated Pacific islands on which it occurs. These islands include Micronesia and Melanesia. In Hawaii, P. tectorius is found natively on all the main islands except Kahoʻolawe, and it is known to have predated human settlement, based on seed and pollen samples taken from Kauaʻi's Makauwahi Cave.

Pandanus tectorius naturally grows in coastal regions, such as on mangrove margins and beaches, at elevations from sea level to 610 m (2,000 ft). It requires 1,500–4,000 mm (59–157 in) of annual rainfall and seasons will fluctuate from wet to dry.

Pandanus tectorius is considered more drought tolerant than coconut trees. The trees have adapted to drought by reducing fruiting. Thatch Screwpine is well adapted to grow in the many soil types present on coasts, including quartz sand, coral sand, and peat, as well as in limestone and basalt. P. tectorius is salt and wind tolerant and favors slightly acidic to basic soil (pH of 6–10). The trees are strong and can typically withstand tropical storms. It prefers to grow in full sunlight, but grows well with 30-50% shade. It will not tolerate shade above 70%.

Ecology

There are a wide range of natural enemies that pose a threat to P. tectorius such as parasites, pathogens, and herbivores. They attack the leaves, roots, stems, and growing points. The stick insect Megacrania batesii lives and feeds only on P. tectorius and two other Pandanus species.

Pandanus tectorius in Australia is threatened by a sap-sucking insect, Jamella australiae, a species of the genus Jamella of the subfamily Flatinae, known as the Pandanus planthopper. It has caused much damage to plants on the northern coast of New South Wales, before making its way up the coast to Noosa and the Gold Coast in Queensland in the 1990s. Since then it has infested pandanus further north, killing about 80 per cent of the P. tectorius population to the south of Gladstone, Queensland, and has since reached Yeppoon on the Capricorn Coast, where P. tectorius plays an important part in preventing coastal erosion. A natural predator in the form of a wasp native to northern Queensland, Aphanomerus pusillus, has been introduced on Fraser Island and in Byfield National Park as one of methods used to combat the pest. Other methods used on Fraser Island including the injection of insecticide into the plant, stripping infested leaves away, and breeding new plants from local stock. The wasp can only be used in the warmer months on the island, as it does not thrive in the cooler climate of southern Queensland.

Cultivation

Pandanus tectorius may be grown from seed or cuttings – the former will flower at around 15 years and the latter usually flowers by 3 to 4 years of age. Female trees typically flower one to three times per year while male trees will flower every 2 months. It is thought to reproduce sexually in Hawaii, but there is some evidence that apomixis occurs. Small insects, such as bees, and wind are usually the pollinators. It takes 1 to 2 years from pollination to produce fruit on female trees.

Seasons vary amongst locations and varieties. For example, in Fiji the pollination season is March to May, in northern Australia it is April to August, and in Micronesia, there are two season December to March and July to September. Most varieties produce 8 to 12 fruits per tree every 2 years. Each fruit usually weighs between 7 and 15 kg (15 and 33 lb) and contains 35 to 80 edible keys.

Pandanus tectorius plants are usually propagated by seed in Hawaii. Soak the keys in cool tap water for 5 days while frequently changing the water. Viable keys will float, so it is important to keep them. In Growing native Hawaiian plants: a how-to guide for the gardner, Bornhorst says to remove the fleshy layer of the key and then bury the seed half-way in planting soil. It is important to keep the soil moist.

P. tectorius can also be grown from large cuttings. Selected forms are propagated by stem cuttings in Micronesia. Morphological traits looked for include aerial roots. Plants selected have two-thirds of their leaves trimmed off to prevent water loss. In Native Hawaiian plants for tropical seaside landscaping, Moriarty says for best results use mature branches with leaves and small aerial roots. Then root in a sand bed. Plants grown from cuttings produce fruit in 4 to 6 years.

Propagation by grafting is not applicable.

Uses

The fruit is edible. Some varieties and cultivars contain significant amounts of calcium oxalate, and thus need thorough cooking before being consumed. Other cultivars contain very little to no calcium oxalate and can be eaten raw. It is an important food source in the atolls of Micronesia and Polynesia, with the fruit commonly eaten raw or turned into a dried paste (such as mokwan in the Marshall Islands or te tuae in Kiribati) or flour. It is also one of the traditional foods of Maldivian cuisine. The fibrous nature of the fruit also serves as a natural dental floss. It is also used in Samoan culture as a ula fala, a necklace made out of the dried fruit painted in red and worn by the matai during special occasions and functions.

Australian Aboriginal peoples extracted the slender, edible seeds. This seed, and the fruit, was an important food.

The tree's leaves are often used as flavoring for sweet dishes. It is also used in Sri Lankan cookery, where the leaves are used to flavor a variety of curries. Leaves were used by the Polynesians to make baskets, mats, outrigger canoe sails, thatch roofs, and grass skirts.

The fragrant male flowers are used in perfumery and are also distilled to make kewra.

A large shrub or small tree of immense cultural, health, and economic importance in the Pacific, it is second only to coconut on atolls. It grows wild mainly in semi-natural vegetation in littoral habitats throughout the tropical and subtropical Pacific, where it can withstand drought, strong winds, and salt spray. It propagates readily from seed, but it is also widely propagated from branch cuttings by local people for farms and home gardens. It grows fairly quickly, and all parts are used, from the nutritious fruits of edible varieties to the poles and branches in construction to the leaves for weaving and garlands. The plant is prominent in Pacific culture and tradition, including local medicine.Template:Citation needed paragraph

Hundreds of cultivated varieties are known by their local names and characteristics of fruits, branches, and leaves. At present, there is evidence that this diversity is declining, with certain varieties becoming difficult to find. The reasons include less replanting, deforestation, fire, flagging interest by the new generation, and rapid population growth leading to urbanization.

In culture

The seal of Punahou School in Honolulu, Hawaii, features the hala tree, in part because lauhala, the art of weaving with the leaves of that tree, is pivotal to the history of the island, with everything from houses to pillows being made in this fashion. Local legend tells of an aged Hawaiian couple who lived long ago above the present Punahou campus, and had to travel far for water. They prayed each night for a spring, but to no avail. Finally one night, in a dream answering their prayers, they were told to uproot the stump of an old hala tree. They did as they were told and found a spring of clear, sweet water, which they named Ka Punahou, the New Spring. According to legend, Punahou School's lily pond is fed by this same spring.Template:Citation needed paragraph

Gallery

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  Ripe fruit
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  Fruit
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  Roots
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  Close up of keys, or stamen
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  Aerial roots trained as an arch, Guam Zoo

See also

• Domesticated plants and animals of Austronesia

External links

• Pandanus tectorius from Foster Garden, Honolulu, Oahu Island, Hawaiʻi World plants, visual gallery University of Murcia. Spain
• NSW Department of Environment & Climate Change [1]
• Australian Native Plants - John W. Wrigley & Murray Fagg ISBN 1-876334-90-8 Search this book on .
• Christenhusz, M.J.M. (2009). Typification of ornamental plants: Pandanus tectorius (Pandanaceae). Phytotaxa 2: 51–52.
• The World's Best Photos of puhala, Flickr Hive Mind, flickrhivemind.net, related pictures, also the fruits partially dismantled

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