''Eugeissona'' is a clustering

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

flowering plant Flowering plants are plants that bear flowers and fruits, and form the clade Angiospermae (). The term angiosperm is derived from the Ancient Greek, Greek words (; 'container, vessel') and (; 'seed'), meaning that the seeds are enclosed with ...

in the

palm Palm most commonly refers to: * Palm of the hand, the central region of the front of the hand * Palm plants, of family Arecaceae ** List of Arecaceae genera **Palm oil * Several other plants known as "palm" Palm or Palms may also refer to: Music ...

family native to

Borneo Borneo () is the List of islands by area, third-largest island in the world, with an area of , and population of 23,053,723 (2020 national censuses). Situated at the geographic centre of Maritime Southeast Asia, it is one of the Greater Sunda ...

Thailand Thailand, officially the Kingdom of Thailand and historically known as Siam (the official name until 1939), is a country in Southeast Asia on the Mainland Southeast Asia, Indochinese Peninsula. With a population of almost 66 million, it spa ...

and

Malaysia Malaysia is a country in Southeast Asia. Featuring the Tanjung Piai, southernmost point of continental Eurasia, it is a federation, federal constitutional monarchy consisting of States and federal territories of Malaysia, 13 states and thre ...

. The six

monoecious Monoecy (; adj. monoecious ) is a sexual system in seed plants where separate male and female cones or flowers are present on the same plant. It is a monomorphic sexual system comparable with gynomonoecy, andromonoecy and trimonoecy, and contras ...

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

provide a wide range of local uses and are commonly called bertam or wild Bornean sago. The genus is the sole representative of the Eugeissoninae having very few obvious relatives; the

hermaphrodite A hermaphrodite () is a sexually reproducing organism that produces both male and female gametes. Animal species in which individuals are either male or female are gonochoric, which is the opposite of hermaphroditic. The individuals of many ...

and staminate flowers are also found in ''

Metroxylon ''Metroxylon'' is a genus of monoecious flowering plants in the Arecaceae (palm) family, and commonly called the ''sago palms'' consisting of seven species. They are native to Western Samoa, New Guinea, the Solomon Islands, the Moluccas, the C ...

'', however the other specialized characteristics are unique suggesting an early split and differentiation from other members of the

Calameae CalameaeKunth CS ex Lecoq & Juillet (1831) ''Dictionnaire raisonne des termes de botanique'' 98. is a palm tree tribe in the subfamily Calamoideae. The type genus is ''Calamus (palm), Calamus'' and many of its members are rattans. Genera * ''C ...

.Uhl, Natalie W. and Dransfield, John (1987) ''Genera Palmarum - A classification of palms based on the work of Harold E. Moore''. Lawrence, Kansas: Allen Press. / Fossilized

pollen Pollen is a powdery substance produced by most types of flowers of seed plants for the purpose of sexual reproduction. It consists of pollen grains (highly reduced Gametophyte#Heterospory, microgametophytes), which produce male gametes (sperm ...

belonging to these plants has been recovered in the lower and middle

Miocene The Miocene ( ) is the first epoch (geology), geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and mea ...

deposits in

Sarawak Sarawak ( , ) is a States and federal territories of Malaysia, state of Malaysia. It is the largest among the 13 states, with an area almost equal to that of Peninsular Malaysia. Sarawak is located in East Malaysia in northwest Borneo, and is ...

. The name is from two

Greek Greek may refer to: Anything of, from, or related to Greece, a country in Southern Europe: *Greeks, an ethnic group *Greek language, a branch of the Indo-European language family **Proto-Greek language, the assumed last common ancestor of all kno ...

words meaning "good" and "roof", due to their common use in roof

thatching Thatching is the craft of building a roof with dry vegetation such as straw, water reed, sedge ('' Cladium mariscus''), rushes, heather, or palm branches, layering the vegetation so as to shed water away from the inner roof. Since the bulk of ...

Description

All of the ''Eugeissona'' palms will form above-ground stems where the apical inflorescence will appear toward the final year of the palm life. For the highland natives of Borneo they let the ''E. utilis'' palm grow trunk and harvest it just before flowering for its palm heart and the starch (

sago Sago () is a starch extracted from the pith, or spongy core tissue, of various tropical palm stems, especially those of ''Metroxylon sagu''. It is a major staple food for the lowland peoples of New Guinea and the Maluku Islands, where it is c ...

) found inside. Amongst the lowland native, the much sought-after palm heart is harvested before the trunk has been formed. During trunk-forming they are supported by tall masses of stilt roots in which detritus and leaf matter collect, providing nesting to various biota. The large leaves are carried on long, spiny petioles, and the rachises and trunks are also spine-bearing. The erect inflorescence bears some of the largest flowers in the palm family, emerging within the leaf crown featuring both male and bisexual flowers. The fruit is a beaked, ovoid drupe carrying one seed.Riffle, Robert L. and Craft, Paul (2003) ''An Encyclopedia of Cultivated Palms''. Portland: Timber Press. /

Floral microbiome

'' Eugeissona tristis'', from West Malaysia, is adapted to promote microbial growth in its flowers. It bears robust, long-lived (sometimes over 4 months) flowers which contain abundant yeast populations. In the central chambers of these flowers, yeast fermentation generates a nectar that is almost 4% ethanol. The palm is pollinated by mammals (squirrels, nocturnal murids, and treeshews like the pentailed treeshrew) which have adapted to chronic alcohol consumption.

Distribution and habitat

They inhabit a variety of settings including the low-lying

heath A heath () is a shrubland habitat found mainly on free-draining infertile, acidic soils and is characterised by open, low-growing woody vegetation. Moorland is generally related to high-ground heaths with—especially in Great Britain—a coole ...

forests,

montane Montane ecosystems are found on the slopes of mountains. The alpine climate in these regions strongly affects the ecosystem because temperatures lapse rate, fall as elevation increases, causing the ecosystem to stratify. This stratification is ...

rain forest Rainforests are forests characterized by a closed and continuous tree Canopy (biology), canopy, moisture-dependent vegetation, the presence of epiphytes and lianas and the absence of wildfire. Rainforests can be generally classified as tropi ...

s, and

swamp A swamp is a forested wetland.Keddy, P.A. 2010. Wetland Ecology: Principles and Conservation (2nd edition). Cambridge University Press, Cambridge, UK. 497 p. Swamps are considered to be transition zones because both land and water play a role in ...

s, but are most common on scarp faces, hills and rocky ridgetops up to 1000 m. ''E. brachystachys'' and ''E. tristis'' are found solely in Malaysia, while the remainder are Bornean or Thai in origin. ''E. tristis'' has become an effective pest in the Hill Dipterocarp forest where it colonizes cleared timberland preventing the regeneration of various trees.

Cultivation and uses

While not common in cultivation, they are used extensively by locals for a variety of purposes. The

made from ''E. utilis'' trunks forms the staple of the

Penan The Penan are a nomadic indigenous people living in Sarawak and Brunei, although there is only one small community in Brunei; among those in Brunei half have been converted to Islam, even if only superficially. Penan are one of the last such p ...

and

Punan Punan Bah or Punan is an ethnic group found in Sarawak, Malaysia and Kalimantan, Indonesia. The Punan Bah people are distinct and unrelated to the semi-nomadic Penan people. Their name stems from two rivers along the banks of which they have b ...

diet. The seed's

endosperm The endosperm is a tissue produced inside the seeds of most of the flowering plants following double fertilization. It is triploid (meaning three chromosome sets per nucleus) in most species, which may be auxin-driven. It surrounds the Embryo#Pla ...

and the pollen are also known to be consumed. The leaves are used in roof construction, various thatchings, and the manufacture of blinds. The stilt roots of some species are made into walking sticks and toys, while the petioles are fashioned into

darts Darts is a competitive sport in which two or more players bare-handedly throw small projectile point, sharp-pointed projectile, projectiles known as dart (missile), darts at a round shooting target, target known as a #Dartboard, dartboard. Point ...

for

blowgun A blowgun (also called a blowpipe or blow tube) is a simple ranged weapon consisting of a long narrow tube for shooting light projectiles such as darts. It operates by having the projectile placed inside the pipe and using the force created by ...

hunting.

References

External links

''Eugeissona'' on NPGS/GRINGBIF PortalFairchild Guide to Palms: ''Eugeissona''
{{Taxonbar, from1=Q139312, from2=Q21445617 Calamoideae Arecaceae genera Flora of Borneo Flora of Peninsular Malaysia Flora of Thailand Taxa named by William Griffith (botanist)