''Dictyosperma'' is a

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 "unisp ...

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 found in the

Mascarene Islands The Mascarene Islands (, ) or Mascarenes or Mascarenhas Archipelago is a group of islands in the Indian Ocean east of Madagascar consisting of islands belonging to the Republic of Mauritius as well as the French department of Réunion. Their na ...

in the

Indian Ocean The Indian Ocean is the third-largest of the world's five oceanic divisions, covering or approximately 20% of the water area of Earth#Surface, Earth's surface. It is bounded by Asia to the north, Africa to the west and Australia (continent), ...

(

Mauritius Mauritius, officially the Republic of Mauritius, is an island country in the Indian Ocean, about off the southeastern coast of East Africa, east of Madagascar. It includes the main island (also called Mauritius), as well as Rodrigues, Ag ...

Réunion Réunion (; ; ; known as before 1848) is an island in the Indian Ocean that is an overseas departments and regions of France, overseas department and region of France. Part of the Mascarene Islands, it is located approximately east of the isl ...

and

Rodrigues Rodrigues ( ; Mauritian Creole, Creole: ) is a Autonomous administrative division, autonomous Outer islands of Mauritius, outer island of the Republic of Mauritius in the Indian Ocean, about east of Mauritius. It is part of the Mascarene Isl ...

). The sole

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), ...

, ''Dictyosperma album'', is widely cultivated in the

tropics The tropics are the regions of Earth surrounding the equator, where the sun may shine directly overhead. This contrasts with the temperate or polar regions of Earth, where the Sun can never be directly overhead. This is because of Earth's ax ...

but has been farmed to near

extinction Extinction is the termination of an organism by the death of its Endling, last member. A taxon may become Functional extinction, functionally extinct before the death of its last member if it loses the capacity to Reproduction, reproduce and ...

in its native habitat. It is commonly called princess palm or hurricane palm, the latter owing to its ability to withstand strong winds by easily shedding leaves.Riffle, Robert L. and Craft, Paul (2003) ''An Encyclopedia of Cultivated Palms''. Portland: Timber Press. / It is closely related to, and resembles, palms in the genus ''

Archontophoenix ''Archontophoenix'' is a plant genus comprising six palm species that are native to New South Wales and Queensland in eastern Australia. They are tall, slender and unbranched. Relationships between ''Archontophoenix'' and the other genera of subt ...

''. The genus is named 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 "net" and "seed" and the epithet is

Latin Latin ( or ) is a classical language belonging to the Italic languages, Italic branch of the Indo-European languages. Latin was originally spoken by the Latins (Italic tribe), Latins in Latium (now known as Lazio), the lower Tiber area aroun ...

for "white", the common color of the crownshaft at the top of the trunk.

Description

The ringed trunks are solitary at 15 cm in diameter with a slight bulge at the base, occasionally reaching up to 12 m in height. The

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 (most notable being ''Roystonea regia'' or the royal palm but also including the genera ''Areca' ...

is over a meter tall, swollen at the base, and covered in white wax— which has given the palm its epithet ''album''— and small, matted brown hairs, producing a rounded leaf crown 4.5 m wide and 3 m tall. The 2.5 to 3 m

leaves A leaf (: leaves) is a principal appendage of the stem of a vascular plant, usually borne laterally above ground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", while the leaves, stem, ...

are borne on short 30 cm petioles; the arching leaflets are pointed at the apice, from 60 – 90 cm, dark green in color, and emerge from the rachis in a single plane. On flowering, they produce up to six

inflorescence In botany, an inflorescence is a group or cluster of flowers arranged on a plant's Plant stem, stem that is composed of a main branch or a system of branches. An inflorescence is categorized on the basis of the arrangement of flowers on a mai ...

s which ring the trunk below the crownshaft, branched to one order, with white to yellow

flower Flowers, also known as blooms and blossoms, are the reproductive structures of flowering plants ( angiosperms). Typically, they are structured in four circular levels, called whorls, around the end of a stalk. These whorls include: calyx, m ...

s, which are

male and female ''Male and Female'' is a 1919 American silent adventure/drama film directed by Cecil B. DeMille and starring Gloria Swanson and Thomas Meighan. Its main themes are gender relations and social class. The film is based on the 1902 J. M. Barri ...

; both pistillate and staminate flowers have three sepals and three

petal Petals are modified leaves that form an inner whorl surrounding the reproductive parts of flowers. They are often brightly coloured or unusually shaped to attract pollinators. All of the petals of a flower are collectively known as the ''corol ...

s, the former being smaller than the latter. The ovoid

fruit In botany, a fruit is the seed-bearing structure in flowering plants (angiosperms) that is formed from the ovary after flowering. Fruits are the means by which angiosperms disseminate their seeds. Edible fruits in particular have long propaga ...

ripen to purple or black in color, containing one brown, ellipsoidal

seed In botany, a seed is a plant structure containing an embryo and stored nutrients in a protective coat called a ''testa''. More generally, the term "seed" means anything that can be Sowing, sown, which may include seed and husk or tuber. Seeds ...

. Three

varieties Variety may refer to: Arts and entertainment Entertainment formats * Variety (radio) * Variety show, in theater and television Films * ''Variety'' (1925 film), a German silent film directed by Ewald Andre Dupont * ''Variety'' (1935 film), ...

are currently recognized: * ''Dictyosperma album'' var. ''album'' (Bory) Scheff. -

* ''Dictyosperma album'' var. ''aureum'' Balf.f. in J.G.Baker -

Rodrigues Island Rodrigues ( ; Creole: ) is a autonomous outer island of the Republic of Mauritius in the Indian Ocean, about east of Mauritius. It is part of the Mascarene Islands, which include Mauritius and Réunion. Like Agaléga, Rodrigues is a consti ...

* ''Dictyosperma album'' var. ''conjugatum'' H.E.Moore & J.Guého - 2 remaining specimens on Île Ronde of Mauritius (Characterised by shorter trunk and white leaf-scar)

Distribution and habitat

Living in the coastal

forest A forest is an ecosystem characterized by a dense ecological community, community of trees. Hundreds of definitions of forest are used throughout the world, incorporating factors such as tree density, tree height, land use, legal standing, ...

s of the Mascarenes, they experience warm temperatures, high humidity and regular rainfall.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. /

''Asterolecanium dictyospermae''

'' Asterolecanium dictyospermae'' is a species of sap sucking scale insect found only on Île Ronde on the two remaining ''Dictyosperma album'' var. ''conjugatum'' specimens. It apparently evolved on Île Ronde and became restricted to feeding upon the island's endemic variety, and due to interbreeding (between varieties) on Mauritius itself which jeopardized reproductive potential, the scale insect increased in population as a result of stress upon the host, which then threatens the existence of both host and scale insect. Image:Dictyosperma album big foot with roots.JPG, Trunk base and

root In vascular plants, the roots are the plant organ, organs of a plant that are modified to provide anchorage for the plant and take in water and nutrients into the plant body, which allows plants to grow taller and faster. They are most often bel ...

s Image:Dictyosperma album seedlings.JPG, Seedlings with bifid eophyll Image:Dictyosperma album1.JPG, Leaf crown Image:Dictyosperma_album_var._conjugatum.JPG, Dictyosperma album var. conjugatum

References

External links

''Dictyosperma images''

''Dictyosperma'' on NPGS/GRIN
*
GBIF Portal

Fairchild Guide to Palms: ''Dictyosperma''

Floridata site
{{Taxonbar, from1=Q16060603, from2=Q3141626 Endemic flora of the Mascarene Islands Areceae Monotypic Arecaceae genera