Pandanus christmatensis
Encyclopedia
Pandanus christmatensis is a dioecious
tropical plant in the screwpine genus
. It is endemic to Christmas Island
, an Australia
n territory in the north-eastern Indian Ocean
. The specific epithet, "christmatensis", comes from its native locality.
, that grows to 10 m in height. Its leaves
are 1–2 m long and 50–80 mm wide, dark green and with marginal prickles. The inflorescence
has white bract
s. The fruit is orange when ripe.
of the island, often next to the sea, on exposed limestone
cliffs with little soil. It also occurs inland beneath the rainforest
canopy, particularly on limestone scree
.
, which is widely distributed through the region, and is very similar to P. platycarpus from Zanzibar
.
Dioecious
Dioecy is the property of a group of biological organisms that have males and females, but not members that have organs of both sexes at the same time. I.e., those whose individual members can usually produce only one type of gamete; each individual organism is thus distinctly female or male...
tropical plant in the screwpine genus
Pandanus
Pandanus is a genus of monocots with about 600 known species. They are numerous palmlike dioecious trees and shrubs native of the Old World tropics and subtropics. They are classified in the order Pandanales, family Pandanaceae.-Overview:...
. It is endemic to Christmas Island
Christmas Island
The Territory of Christmas Island is a territory of Australia in the Indian Ocean. It is located northwest of the Western Australian city of Perth, south of the Indonesian capital, Jakarta, and ENE of the Cocos Islands....
, an Australia
Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
n territory in the north-eastern Indian Ocean
Indian Ocean
The Indian Ocean is the third largest of the world's oceanic divisions, covering approximately 20% of the water on the Earth's surface. It is bounded on the north by the Indian Subcontinent and Arabian Peninsula ; on the west by eastern Africa; on the east by Indochina, the Sunda Islands, and...
. The specific epithet, "christmatensis", comes from its native locality.
Description
Pandanus christmatensis is a small tree or shrub, with prop rootsAerial root
Aerial roots are roots above the ground. They are almost always adventitious. They are found in diverse plant species, including epiphytes such as orchids, tropical coastal swamp trees such as mangroves, the resourceful banyan trees, the warm-temperate rainforest rātā and pōhutukawa Aerial roots...
, that grows to 10 m in height. Its leaves
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....
are 1–2 m long and 50–80 mm wide, dark green and with marginal prickles. 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...
has white bract
Bract
In botany, a bract is a modified or specialized leaf, especially one associated with a reproductive structure such as a flower, inflorescence axis, or cone scale. Bracts are often different from foliage leaves. They may be smaller, larger, or of a different color, shape, or texture...
s. The fruit is orange when ripe.
Distribution and habitat
The plant forms dense, tangled thickets on the shore terracesMarine terrace
A marine terrace, coastal terrace, raised beach or perched coastline is a relatively flat, horizontal or gently inclined surface of marine origin, mostly an old abrasion platform which has been lifted out of the sphere of wave activity . Thus it lies above or under the current sea level, depending...
of the island, often next to the sea, on exposed limestone
Limestone
Limestone is a sedimentary rock composed largely of the minerals calcite and aragonite, which are different crystal forms of calcium carbonate . Many limestones are composed from skeletal fragments of marine organisms such as coral or foraminifera....
cliffs with little soil. It also occurs inland beneath the rainforest
Rainforest
Rainforests are forests characterized by high rainfall, with definitions based on a minimum normal annual rainfall of 1750-2000 mm...
canopy, particularly on limestone scree
Scree
Scree, also called talus, is a term given to an accumulation of broken rock fragments at the base of crags, mountain cliffs, or valley shoulders. Landforms associated with these materials are sometimes called scree slopes or talus piles...
.
Taxonomy
The plant is closely related to P. tectoriusPandanus tectorius
Pandanus tectorius is a species of Pandanus that is native to Malesia, eastern Australia, and the Pacific Islands. Common names include Thatch Screwpine, Hala , Bacua , and Vacquois ....
, which is widely distributed through the region, and is very similar to P. platycarpus from Zanzibar
Zanzibar
Zanzibar ,Persian: زنگبار, from suffix bār: "coast" and Zangi: "bruin" ; is a semi-autonomous part of Tanzania, in East Africa. It comprises the Zanzibar Archipelago in the Indian Ocean, off the coast of the mainland, and consists of numerous small islands and two large ones: Unguja , and Pemba...
.