The karuka (''Pandanus julianettii'', also called karuka nut and ''Pandanus'' nut) is a species of tree in the family

Pandanaceae Pandanaceae is a family of flowering plants native to the tropics and subtropics of the Old World, from West Africa through the Pacific. It contains 982 known species in five genera, of which the type genus, ''Pandanus'', is the most important, wi ...

and an important regional food crop in

New Guinea New Guinea (; Hiri Motu Hiri Motu, also known as Police Motu, Pidgin Motu, or just Hiri, is a language of Papua New Guinea, which is spoken in surrounding areas of Port Moresby (Capital of Papua New Guinea). It is a simplified version of ...

. The nuts are more nutritious than

coconut The coconut tree (''Cocos nucifera'') is a member of the palm tree family ( Arecaceae) and the only living species of the genus ''Cocos''. The term "coconut" (or the archaic "cocoanut") can refer to the whole coconut palm, the seed, or the ...

s, and are so popular that villagers in the

highlands Highland is a broad term for areas of higher elevation, such as a mountain range or mountainous plateau. Highland, Highlands, or The Highlands, may also refer to: Places Albania * Dukagjin Highlands Armenia * Armenian Highlands Australia *Sou ...

will move their entire households closer to trees for the harvest season.

Names

The

specific epithet In taxonomy, binomial nomenclature ("two-term naming system"), also called nomenclature ("two-name naming system") or binary nomenclature, is a formal system of naming species of living things by giving each a name composed of two parts, bot ...

"''julianettii''" honors naturalist Amedeo Giulianetti, who found the original

type specimens In biology, a type is a particular specimen (or in some cases a group of specimens) of an organism to which the scientific name of that organism is formally attached. In other words, a type is an example that serves to anchor or centralizes t ...

. is a

loanword A loanword (also loan word or loan-word) is a word at least partly assimilated from one language (the donor language) into another language. This is in contrast to cognates, which are words in two or more languages that are similar because th ...

from

Tok Pisin Tok Pisin (,Laurie Bauer, 2007, ''The Linguistics Student’s Handbook'', Edinburgh ; Tok Pisin ), often referred to by English speakers as "New Guinea Pidgin" or simply Pidgin, is a creole language spoken throughout Papua New Guinea. It is an ...

. Sometimes the tree is called '' or 'karuka nut pandanus'. The term 'karuka' can apply to both ''Pandanus julianettii'' and '' P. brosimos'', though the latter is usually called 'wild karuka'. Both species, as well as '' P. dubius'', can be called 'pandanus nut'. In addition to ''P. brosimos'', 'wild karuka' can also refer to '' P. antaresensis'', '' P. iwen'', and '' P. limbatus'', but nuts from these trees are a much smaller part of the local diet. In contexts where multiple karuka species are discussed, ''P. julianettii'' is sometimes termed 'planted karuka'. ''P. julianettii'', ''P. iwen'', and ''P. brosimos'' are also in the subsection named ''

Karuka The karuka (''Pandanus julianettii'', also called karuka nut and ''Pandanus'' nut) is a species of tree in the family Pandanaceae and an important regional food crop in New Guinea. The nuts are more nutritious than coconuts, and are so popular ...

'', which is in the

monotypic In biology, a monotypic taxon is a taxonomic group (taxon) that contains only one immediately subordinate taxon. A monotypic species is one that does not include subspecies or smaller, infraspecific taxa. In the case of genera, the term "unispec ...

section Section, Sectioning or Sectioned may refer to: Arts, entertainment and media * Section (music), a complete, but not independent, musical idea * Section (typography), a subdivision, especially of a chapter, in books and documents ** Section sign ...

also named ''

''. In

it goes by different names among each of the

Papuan people The indigenous peoples of West Papua in Indonesia and Papua New Guinea, commonly called Papuans, are Melanesians. There is genetic evidence for two major historical lineages in New Guinea and neighboring islands: a first wave from the Malay Arc ...

s. In the

Ankave language Ankave or Angave is a Papuan language spoken by the approximately 1,600 () Angave people in Kerema District, Gulf Province, Papua New Guinea. Phonology Vowels Diphthongs: Consonants Writing system An orthography using the Latin script has ...

it is . It is in the

Baruya language Yipma (pronounced as ''Hipma'') is an Angan language of Papua New Guinea Papua New Guinea (abbreviated PNG; , ; tpi, Papua Niugini; ho, Papua Niu Gini), officially the Independent State of Papua New Guinea ( tpi, Independen Stet bilo ...

. The

Huli language Huli is a Tari language spoken by the Huli people of the Hela Province of Papua New Guinea. It has a pentadecimal (base-15) numeral system: means 15, means 15×2 = 30, and means 15×15 = 225. Huli has a pandanus language called (bush divid ...

word is , and it is also in the

Duna language Duna (also known as ''Yuna'') is a Papuan language of Papua New Guinea. It may belong to the Trans New Guinea language family and is often further classified as a Duna-Pogaya language, for Bogaya appears to be Duna's closest relative, as eviden ...

. In

Kewa language Kewa is an Engan language complex of the Southern Highlands province of Papua New Guinea. A dictionary of the western dialect of Kewa has been compiled by . Kewa pandanus register Kewa's elaborate pandanus avoidance register, which is used on ...

it is ''aga'', but it is unclear which dialect(s). In the Kewa

pandanus language A pandanus language is an elaborate avoidance language among several of the peoples of the eastern New Guinea Highlands, used when collecting ''Pandanus'' nuts. Use Annually, people camp in the forest to harvest and cook the nuts of karuka (both ...

it is ''rumala agaa''. The

Kalam language Kalam is a Kalam language of Papua New Guinea. It is closely related to Kobon, and shares many of the features of that language. Kalam is spoken in Middle Ramu District of Madang Province and in Mount Hagen District of Western Highlands Provinc ...

term, in both standard and pandanus languages, is , but it can also be called or . The plant is called in the

Wiru language Wiru or Witu is the language spoken by the Wiru people of Ialibu-Pangia District of the Southern Highlands Province of Papua New Guinea Papua New Guinea (abbreviated PNG; , ; tpi, Papua Niugini; ho, Papua Niu Gini), officially the I ...

. In the

Pole language Kewa is an Engan language complex of the Southern Highlands province of Papua New Guinea. A dictionary of the western dialect of Kewa has been compiled by . Kewa pandanus register Kewa's elaborate pandanus avoidance register, which is used on ...

it's called ''maisene''. It goes by ''ank'' in

Angal language Angal, or Mendi, is an Engan language complex of the Southern Highlands province of Papua New Guinea. Mendi has a pandanus language used during karuka The karuka (''Pandanus julianettii'', also called karuka nut and ''Pandanus'' nut) is a ...

, and in the Wola dialect. The Imbongu language word is . The plant also has many names on the other half of the island. In

Indonesian Indonesian is anything of, from, or related to Indonesia, an archipelagic country in Southeast Asia. It may refer to: * Indonesians, citizens of Indonesia ** Native Indonesians, diverse groups of local inhabitants of the archipelago ** Indonesian ...

it is called ( lit.) and (), but the latter can also refer to ''P. brosimos'' and ''P. iwen''. The Dani people call it ''tuke''. The

Lani people The Lani are an indigenous people in Puncak, Central Papua and Lanny Jaya, Highland Papua, usually labelled 'Western Dani' by foreign missionaries, or grouped—inaccurately—with the Dani people who inhabit the Baliem Valley to the east. Po ...

call it , but this might be a separate species in the

complex Complex commonly refers to: * Complexity, the behaviour of a system whose components interact in multiple ways so possible interactions are difficult to describe ** Complex system, a system composed of many components which may interact with each ...

Description

The species was originally described by

Ugolino Martelli Ugolino Martelli (1860–1934) was an Italian botanist, biologist, and mycology, mycologist. Martelli is known for his studies of and contributions to the systematics of the tropical genus ''Pandanus'' and his taxonomic definition of the flora of ...

from only a few

drupe In botany, a drupe (or stone fruit) is an indehiscent fruit in which an outer fleshy part (exocarp, or skin, and mesocarp, or flesh) surrounds a single shell (the ''pit'', ''stone'', or '' pyrena'') of hardened endocarp with a seed (''kernel'') ...

s in the collections of the

Royal Botanic Gardens, Kew Royal Botanic Gardens, Kew is a non-departmental public body in the United Kingdom sponsored by the Department for Environment, Food and Rural Affairs. An internationally important botanical research and education institution, it employs 1,100 ...

He was hesitant to describe it as a new species from only that, but the characteristics were so salient he published his description. The tree is

dioecious Dioecy (; ; adj. dioecious , ) is a characteristic of a species, meaning that it has distinct individual organisms (unisexual) that produce male or female gametes, either directly (in animals) or indirectly (in seed plants). Dioecious reproductio ...

(individual plants either have male flowers or female ones), with male trees uncommon compared to females. It reaches in height, with a grey

trunk Trunk may refer to: Biology * Trunk (anatomy), synonym for torso * Trunk (botany), a tree's central superstructure * Trunk of corpus callosum, in neuroanatomy * Elephant trunk, the proboscis of an elephant Computing * Trunk (software), in rev ...

of in diameter and supported by

buttress root Buttress roots also known as plank roots are large, wide roots on all sides of a shallowly rooted tree. Typically, they are found in nutrient-poor tropical forest soils that may not be very deep. They prevent the tree from falling over (hence t ...

s. The trunk has white mottling and is generally smooth with occasional warts or small knobs as well as rings of

leaf scar A leaf scar is the mark left by a leaf after it falls off the twig. It marks the site where the petiole attached to the stem. A leaf scar is typically found below a branch as branches come from axillary buds located above leaf scars. Formation Le ...

s. Inside the trunk is pithy and lacking

cambium A cambium (plural cambia or cambiums), in plants, is a tissue layer that provides partially undifferentiated cells for plant growth. It is found in the area between xylem and phloem. A cambium can also be defined as a cellular plant tissue from w ...

. The top of the tree sometimes branches, producing three or four crowns of leaves. Each crown will produce a single cluster of nuts, typically once every other season. Production is affected by the seasonality of local rainfall.

Leaves A leaf (plural, : leaves) is any of the principal appendages of a vascular plant plant stem, stem, usually borne laterally aboveground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", wh ...

spiral up the trunk in opposite pairs. The large leathery leaves are long and wide. The apex of the leaf is

attenuate In physics, attenuation (in some contexts, extinction) is the gradual loss of flux intensity through a medium. For instance, dark glasses attenuate sunlight, lead attenuates X-rays, and water and air attenuate both light and sound at variable a ...

and doubly-pleated, with prickles pointing up at the tip and along the

margins Margin may refer to: Physical or graphical edges *Margin (typography), the white space that surrounds the content of a page *Continental margin, the zone of the ocean floor that separates the thin oceanic crust from thick continental crust *Leaf ...

and

midrib This glossary of botanical terms is a list of definitions of terms and concepts relevant to botany and plants in general. Terms of plant morphology are included here as well as at the more specific Glossary of plant morphology and Glossary o ...

. The leaves are dark green on top and dull cyan underneath. The

inflorescence An inflorescence is a group or cluster of flowers arranged on a stem that is composed of a main branch or a complicated arrangement of branches. Morphologically, it is the modified part of the shoot of seed plants where flowers are formed o ...

on male trees is a densely-branched spadix with a dozen long spikes, each containing many

staminate The stamen (plural ''stamina'' or ''stamens'') is the pollen-producing reproductive organ of a flower. Collectively the stamens form the androecium., p. 10 Morphology and terminology A stamen typically consists of a stalk called the filam ...

phalanges. In each phalange is a

column A column or pillar in architecture and structural engineering is a structural element that transmits, through compression, the weight of the structure above to other structural elements below. In other words, a column is a compression member. ...

3 mm long topped by up to 9

subsessile In botany, sessility (meaning "sitting", used in the sense of "resting on the surface") is a characteristic of plant parts (such as flowers and leaves) that have no stalk. Plant parts can also be described as subsessile, that is, not completely ...

anther The stamen (plural ''stamina'' or ''stamens'') is the pollen-producing reproductive organ of a flower. Collectively the stamens form the androecium., p. 10 Morphology and terminology A stamen typically consists of a stalk called the filam ...

s. The male flowers are white, and the whole male flowering organ may be up to long. The

pollen Pollen is a powdery substance produced by seed plants. It consists of pollen grains (highly reduced microgametophytes), which produce male gametes (sperm cells). Pollen grains have a hard coat made of sporopollenin that protects the gametophyt ...

has a

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