Actinorhytis
Encyclopedia
Actinorhytis is a monotypic
genus
of flowering plant
in the palm
family found in Oceania
. The lone species
, Actinorhytis calapparia is a rain forest inhabitant and has the largest fruit
of any palm in the Iguanurinae. The genus name is from two Greek
words meaning 'ray' and 'fold' which describe the endosperm
of the seed
.
s and are topped by a distinct 1 m, crownshaft
, slightly bulging at the base. The leaf crown is sparse but spherical, each arching leaf
is around 3 m long with pinnately arranged, 45 cm leaflets which are dark green in color. The leaflets are closely and regularly arranged along the rachis and the abaxially rounded petiole
is usually long in youth but shorter in maturity.
The much branched monoecious inflorescence
forms below the leaf bases, ringing the trunk with cream colored male and female flowers. Both sexes carry three sepals and three petals and in both cases the sepals are two or three times longer than the petals. The inflorescence becomes pendent as the large fruit set; the beaked, ovoid fruit are red to purple to green; each fruit contains one seed
.
and the Solomon Islands
thriving in lowland rain forest from sea level to 1000 m. While understory subjects for much of their life, they eventually reach the top of the forest canopy.
and Malesia
where villagers attribute it magical or medicinal powers, or as a substitute to betel
. They have little tolerance for drought, requiring generous water as well as nutrient rich soil; they do, however, exhibit some tolerance to cold.
Monotypic
In biology, a monotypic taxon is a taxonomic group with only one biological type. The term's usage differs slightly between botany and zoology. The term monotypic has a separate use in conservation biology, monotypic habitat, regarding species habitat conversion eliminating biodiversity and...
genus
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 found in Oceania
Oceania
Oceania is a region centered on the islands of the tropical Pacific Ocean. Conceptions of what constitutes Oceania range from the coral atolls and volcanic islands of the South Pacific to the entire insular region between Asia and the Americas, including Australasia and the Malay Archipelago...
. The lone species
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
, Actinorhytis calapparia is a rain forest inhabitant and has the largest 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,...
of any palm in the Iguanurinae. The genus name is from two Greek
Greek language
Greek is an independent branch of the Indo-European family of languages. Native to the southern Balkans, it has the longest documented history of any Indo-European language, spanning 34 centuries of written records. Its writing system has been the Greek alphabet for the majority of its history;...
words meaning 'ray' and 'fold' which describe the endosperm
Endosperm
Endosperm is the tissue produced inside the seeds of most flowering plants around the time of fertilization. It surrounds the embryo and provides nutrition in the form of starch, though it can also contain oils and protein. This makes endosperm an important source of nutrition in human diet...
of the 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...
.
Description
The species is solitary trunked, reaching 12 to 14 m in height, and is relatively slender, usually no wider than 20 cm. At the base, the white to tan trunks are anchored by a large, conical mass of aerial rootRoot
In vascular plants, the root is the organ of a plant that typically lies below the surface of the soil. This is not always the case, however, since a root can also be aerial or aerating . Furthermore, a stem normally occurring below ground is not exceptional either...
s and are topped by a distinct 1 m, crownshaft
Crownshaft
An elongated circumferential leaf base formation present on some species of palm is called a crownshaft.The leaf bases of some pinnate leaved palms form a sheath at the top of the trunk surrounding the bud where all the subsequent leaves are formed.The crownshaft...
, slightly bulging at the base. The leaf crown is sparse but spherical, each arching leaf
Leaf
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....
is around 3 m long with pinnately arranged, 45 cm leaflets which are dark green in color. The leaflets are closely and regularly arranged along the rachis and the abaxially rounded petiole
Petiole (botany)
In botany, the petiole is the stalk attaching the leaf blade to the stem. The petiole usually has the same internal structure as the stem. Outgrowths appearing on each side of the petiole are called stipules. Leaves lacking a petiole are called sessile, or clasping when they partly surround the...
is usually long in youth but shorter in maturity.
The much branched monoecious 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...
forms below the leaf bases, ringing the trunk with cream colored male and female flowers. Both sexes carry three sepals and three petals and in both cases the sepals are two or three times longer than the petals. The inflorescence becomes pendent as the large fruit set; the beaked, ovoid fruit are red to purple to green; each fruit contains one 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...
.
Distribution and habitat
These palms are endemic to New GuineaNew 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...
and the Solomon Islands
Solomon Islands
Solomon Islands is a sovereign state in Oceania, east of Papua New Guinea, consisting of nearly one thousand islands. It covers a land mass of . The capital, Honiara, is located on the island of Guadalcanal...
thriving in lowland rain forest from sea level to 1000 m. While understory subjects for much of their life, they eventually reach the top of the forest canopy.
Cultivation and uses
A. calapparia is widely cultivated in Southeast AsiaSoutheast 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...
and Malesia
Malesia
Malesia is a biogeographical region straddling the boundaries of the Indomalaya ecozone and Australasia ecozone, and also a phytogeographical floristic region in the Paleotropical Kingdom.-Floristic province:...
where villagers attribute it magical or medicinal powers, or as a substitute to betel
Betel nut
The Areca nut is the seed of the Areca palm , which grows in much of the tropical Pacific, Asia, and parts of east Africa. It is commonly referred to as "betel nut" as it is often chewed wrapped in betel leaves.-Description:...
. They have little tolerance for drought, requiring generous water as well as nutrient rich soil; they do, however, exhibit some tolerance to cold.