Korthalsia
Encyclopedia
Korthalsia is a clustering genus
of flowering plant
in the palm
family spread throughout Southeast Asia
. It is a highly specialized rattan
with some species known to have an intimate relationship with ants, hence the common name ant rattan. High-climbing and armed with spines, the genus is named for the Dutch
botanist P. W. Korthals
who first collected them from Indonesia
.
are undivided with the occasional bifid apice. A truly pinnate
leaf form comes in maturity and is accompanied by a barbed rachis extension which allows the palm to hook onto forest vegetation and climb to the canopy top where mature pinnae hang pendent. Also unique to the group are the rachis borne stalks, adapted for climbing, from which the leaflets emerge.
Sexually, they are hapaxanthic, another rare feature in palms, which results in the death of individual stems after flowering and fruiting has occurred. As hermaphrodite
s, the flower
s are also uncommon with both male and female organs present in each. The inflorescence
is short and thick, once or twice branched, with bisexual flowers hanging from long, furry stalks. Spherical to ovoid, the fruit
is scaly and matures to orange, red or brown with one basally attached seed
.
Fossilized pollen referable to this genus has been recovered in upper Miocene
deposits in northwest Borneo
; its long history, and its wide variety of unusual features may indicate its climbing habit evolved independently of other rattans.
Bees are observed visitors to the flowers while Anthracoceros
convexus feeds on the fruit.
perhumid region with northern outliers in Indochina
the Andaman Islands
and Burma and south to Sulawesi
and New Guinea
. They are confined to the tropics
where they thrive in low land or hilly rain forest being conspicuously absent in montane
regions; some are narrowly limited to ultrabasic rock while others are adept at colonizing cleared forest
s.
The carnivorous plant
Nepenthes bicalcarata
as well as Macaranga caladiifolia and Clerodendrum fistulosum, grow alongside some Korthalsias in Borneo, and also feature swollen appendages in which ants nest. Other palm genera feature species known to harbor ants, including Laccosperma
, Eremospatha
, Calamus and Daemonorops
.
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
of flowering plant
Flowering plant
The flowering plants , also known as Angiospermae or Magnoliophyta, are the most diverse group of land plants. Angiosperms are seed-producing plants like the gymnosperms and can be distinguished from the gymnosperms by a series of synapomorphies...
in the palm
Arecaceae
Arecaceae or Palmae , are a family of flowering plants, the only family in the monocot order Arecales. There are roughly 202 currently known genera with around 2600 species, most of which are restricted to tropical, subtropical, and warm temperate climates...
family spread throughout Southeast Asia
Southeast Asia
Southeast Asia, South-East Asia, South East Asia or Southeastern Asia is a subregion of Asia, consisting of the countries that are geographically south of China, east of India, west of New Guinea and north of Australia. The region lies on the intersection of geological plates, with heavy seismic...
. It is a highly specialized rattan
Rattan
Rattan is the name for the roughly 600 species of palms in the tribe Calameae, native to tropical regions of Africa, Asia and Australasia.- Structure :...
with some species known to have an intimate relationship with ants, hence the common name ant rattan. High-climbing and armed with spines, the genus is named for the Dutch
Netherlands
The Netherlands is a constituent country of the Kingdom of the Netherlands, located mainly in North-West Europe and with several islands in the Caribbean. Mainland Netherlands borders the North Sea to the north and west, Belgium to the south, and Germany to the east, and shares maritime borders...
botanist P. W. Korthals
Pieter Willem Korthals
Pieter Willem Korthals was a Dutch botanist. Korthals was the official botanist with the Dutch East India Service from 1831 to 1836....
who first collected them from Indonesia
Indonesia
Indonesia , officially the Republic of Indonesia , is a country in Southeast Asia and Oceania. Indonesia is an archipelago comprising approximately 13,000 islands. It has 33 provinces with over 238 million people, and is the world's fourth most populous country. Indonesia is a republic, with an...
.
Description
In young plants the trunks, petioles and rachises are covered in spines. Mature plants typically lose rachis and petiole spines but will retain trunks spines in its new growth. The suckering stems are small to mostly moderate and are among the few in the palm family that branch; among rattans it is the only one with splitting stems. The trunks are bare at the bottom but retain persistent leaf bases in its youngest parts; enlarged paper-like appendages, ocreas, form where the petioles meet the stem. The ocreas are usually grossly swollen and house ants. Younger leavesLeaf
A leaf is an organ of a vascular plant, as defined in botanical terms, and in particular in plant morphology. Foliage is a mass noun that refers to leaves as a feature of plants....
are undivided with the occasional bifid apice. A truly pinnate
Pinnate
Pinnate is a term used to describe feather-like or multi-divided features arising from both sides of a common axis in plant or animal structures, and comes from the Latin word pinna meaning "feather", "wing", or "fin". A similar term is pectinate, which refers to a comb-like arrangement of parts...
leaf form comes in maturity and is accompanied by a barbed rachis extension which allows the palm to hook onto forest vegetation and climb to the canopy top where mature pinnae hang pendent. Also unique to the group are the rachis borne stalks, adapted for climbing, from which the leaflets emerge.
Sexually, they are hapaxanthic, another rare feature in palms, which results in the death of individual stems after flowering and fruiting has occurred. As hermaphrodite
Hermaphrodite
In biology, a hermaphrodite is an organism that has reproductive organs normally associated with both male and female sexes.Many taxonomic groups of animals do not have separate sexes. In these groups, hermaphroditism is a normal condition, enabling a form of sexual reproduction in which both...
s, the flower
Flower
A flower, sometimes known as a bloom or blossom, is the reproductive structure found in flowering plants . The biological function of a flower is to effect reproduction, usually by providing a mechanism for the union of sperm with eggs...
s are also uncommon with both male and female organs present in each. The inflorescence
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. Strictly, it is the part of the shoot of seed plants where flowers are formed and which is accordingly modified...
is short and thick, once or twice branched, with bisexual flowers hanging from long, furry stalks. Spherical to ovoid, the fruit
Fruit
In broad terms, a fruit is a structure of a plant that contains its seeds.The term has different meanings dependent on context. In non-technical usage, such as food preparation, fruit normally means the fleshy seed-associated structures of certain plants that are sweet and edible in the raw state,...
is scaly and matures to orange, red or brown with one basally attached seed
Seed
A seed is a small embryonic plant enclosed in a covering called the seed coat, usually with some stored food. It is the product of the ripened ovule of gymnosperm and angiosperm plants which occurs after fertilization and some growth within the mother plant...
.
Fossilized pollen referable to this genus has been recovered in upper Miocene
Miocene
The Miocene is a geological epoch of the Neogene Period and extends from about . The Miocene was named by Sir Charles Lyell. Its name comes from the Greek words and and means "less recent" because it has 18% fewer modern sea invertebrates than the Pliocene. The Miocene follows the Oligocene...
deposits in northwest Borneo
Borneo
Borneo is the third largest island in the world and is located north of Java Island, Indonesia, at the geographic centre of Maritime Southeast Asia....
; its long history, and its wide variety of unusual features may indicate its climbing habit evolved independently of other rattans.
Bees are observed visitors to the flowers while Anthracoceros
Anthracoceros
Anthracoceros is an Asian genus of the Bucerotidae family . Species included in the genus are:* Malabar Pied Hornbill, Anthracoceros coronatus* Oriental Pied Hornbill, Anthracoceros albirostris...
convexus feeds on the fruit.
Distribution and habitat
The genus is concentrated around the Sunda Shelf'sSunda Shelf
Geologically, the Sunda Shelf is a south east extension of the continental shelf of Southeast Asia. Major landmasses on the shelf include the Malay Peninsula, Sumatra, Borneo, Java, Madura, Bali and their surrounding smaller islands. It covers an area of approximately 1.85 million km2...
perhumid region with northern outliers in Indochina
Indochina
The Indochinese peninsula, is a region in Southeast Asia. It lies roughly southwest of China, and east of India. The name has its origins in the French, Indochine, as a combination of the names of "China" and "India", and was adopted when French colonizers in Vietnam began expanding their territory...
the Andaman Islands
Andaman Islands
The Andaman Islands are a group of Indian Ocean archipelagic islands in the Bay of Bengal between India to the west, and Burma , to the north and east...
and Burma and south to Sulawesi
Sulawesi
Sulawesi is one of the four larger Sunda Islands of Indonesia and is situated between Borneo and the Maluku Islands. In Indonesia, only Sumatra, Borneo, and Papua are larger in territory, and only Java and Sumatra have larger Indonesian populations.- Etymology :The Portuguese were the first to...
and New Guinea
New Guinea
New Guinea is the world's second largest island, after Greenland, covering a land area of 786,000 km2. Located in the southwest Pacific Ocean, it lies geographically to the east of the Malay Archipelago, with which it is sometimes included as part of a greater Indo-Australian Archipelago...
. They are confined to the tropics
Tropics
The tropics is a region of the Earth surrounding the Equator. It is limited in latitude by the Tropic of Cancer in the northern hemisphere at approximately N and the Tropic of Capricorn in the southern hemisphere at S; these latitudes correspond to the axial tilt of the Earth...
where they thrive in low land or hilly rain forest being conspicuously absent in montane
Montane
In biogeography, montane is the highland area located below the subalpine zone. Montane regions generally have cooler temperatures and often have higher rainfall than the adjacent lowland regions, and are frequently home to distinct communities of plants and animals.The term "montane" means "of the...
regions; some are narrowly limited to ultrabasic rock while others are adept at colonizing cleared forest
Forest
A forest, also referred to as a wood or the woods, is an area with a high density of trees. As with cities, depending where you are in the world, what is considered a forest may vary significantly in size and have various classification according to how and what of the forest is composed...
s.
Relationship with ants
Ants of the Camponotus genus have an intimate relationship with several Korthalsia species, occupying chambers in the fibrous and swollen orecas at the leaf bases. Here, the ants "farm" scale insects which feed on the palm’s phloem cells, and produce a sweet dew the ants feed on. The ants also beat their abdomens against the dry leaf bases to create a precautionary alarm rattle before attacking en masse. The relationship seems to be mutual, protecting the palms from herbivores.The carnivorous plant
Carnivorous plant
Carnivorous plants are plants that derive some or most of their nutrients from trapping and consuming animals or protozoans, typically insects and other arthropods. Carnivorous plants appear adapted to grow in places where the soil is thin or poor in nutrients, especially nitrogen, such as acidic...
Nepenthes bicalcarata
Nepenthes bicalcarata
Nepenthes bicalcarata , also known as the Fanged Pitcher-Plant, is a tropical pitcher plant endemic to northwestern Borneo.-Botanical history:...
as well as Macaranga caladiifolia and Clerodendrum fistulosum, grow alongside some Korthalsias in Borneo, and also feature swollen appendages in which ants nest. Other palm genera feature species known to harbor ants, including Laccosperma
Laccosperma
Laccosperma is a clustering genus of flowering plant in the palm family found in tropical Africa. Poorly studied and rarely cultivated, they are closely related to the Eremospatha genus and with it form a tribe in the Calameae characterized by dyads of hermaphrodite flowers...
, Eremospatha
Eremospatha
Eremospatha is a climbing genus of flowering plant in the palm family found in tropical Africa. These rattans are uncommon in cultivation and poorly understood by taxonomists; some 12 species have been described, of which three are commonly recognized. Closely related to Laccosperma, they are...
, Calamus and Daemonorops
Daemonorops
Daemonorops is a genus of rattan palms in the family Arecaceae found primarily in the tropics and subtropics of southeastern Asia.The stems of the Daemonorops are harvest for their cores, which is used for everything from canes to furniture. The fruits of certain species, in particular Daemonorops...
.