''Acanthophoenix'' is a genus of

flowering plant Flowering plants are plants that bear flowers and fruits, and form the clade Angiospermae (), commonly called angiosperms. The term "angiosperm" is derived from the Greek words ('container, vessel') and ('seed'), and refers to those plants th ...

s in the palm family from 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 the islands belonging to the Republic of Mauritius as well as the French department of Réunion. Thei ...

in the

Indian Ocean The Indian Ocean is the third-largest of the world's five oceanic divisions, covering or ~19.8% of the water on Earth's surface. It is bounded by Asia to the north, Africa to the west and Australia to the east. To the south it is bounded by th ...

, where they are commonly called palmiste rouge. A genus long in flux, three

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

are currently recognized, though unsustainable levels of harvesting for their edible palm hearts have brought them all to near extinction in habitat. They are closely related to the ''

Tectiphiala ''Tectiphiala ferox'', or ''palmiste bouglé'', is a species of flowering plant in the family Arecaceae. It is endemic to Mauritius. It is threatened by habitat loss. It is the sole species in the genus ''Tectiphiala''. ''Tectiphiala ferox'' was ...

'' and '' Deckenia'' genera, differing in the shape of the staminate

flower A flower, sometimes known as a bloom or blossom, is the reproductive structure found in flowering plants (plants of the division Angiospermae). The biological function of a flower is to facilitate reproduction, usually by providing a mechani ...

.Uhl, N. W. and J. Dransfield. ''Genera Palmarum - A Classification of Palms Based on the Work of Harold E. Moore''. Lawrence, Kansas: Allen Press. 1987. / The name combines the

Greek Greek may refer to: Greece 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 ...

words for "thorn" and "

date palm ''Phoenix dactylifera'', commonly known as date or date palm, is a flowering plant species in the palm family, Arecaceae, cultivated for its edible sweet fruit called dates. The species is widely cultivated across northern Africa, the Middle Eas ...

".Riffle, R. L. and P. Craft. ''An Encyclopedia of Cultivated Palms''. Portland: Timber Press. 2003. /

Description

The solitary trunks are robust and conspicuously ringed, sparsely armed in youth, with a slightly swollen base. The tubular

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

bases wrap the trunk, forming a 60 – 90 cm

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' ...

covered in hairy tomentum and spines. The leaves are pinnate, 2 m long, and borne on a tomentose petiole, sparsely to densely spiny. The leaflets emerge from the hairy rachis in a flat plane, dark green above and lighter below, to 30 cm long, once-folded with a red or yellow, toothed midrib. The species are monoecious.

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. Morphologically, it is the modified part of the shoot of seed plants where flowers are formed o ...

sprouts at the crownshaft base, branched to two orders with a short, winged, tomentose peduncle, colored brown and bearing spines. There is a single peduncular bract, the rachis long, often spiny, bearing ivory to red rachillae. The flowers are spirally arranged on first order rachillae, subtended by triangular bracts, with pairs or single staminate flowers on the tips; the branchlets elongate and become green in fruit. The staminate flowers are asymmetrical, white to cream to red, the three sepals are short and imbricate, while the three valvate

petal Petals are modified Leaf, leaves that surround the reproductive parts of flowers. They are often advertising coloration, brightly colored or unusually shaped to attract pollinators. All of the petals of a flower are collectively known as the ''c ...

s are three or four times as long. There are up to twelve stamens, exserted at antithesis, on elongated, slender to wide filaments. The anthers are dorsifixed, linear and basally sagittate; the

pollen Pollen is a powdery substance produced by seed plants. It consists of pollen grains (highly reduced microgametophytes), which produce male gametes (sperm cells). Pollen grains have a hard coat made of sporopollenin that protects the gametophyt ...

is monosulcate and elliptic with tectate, reticulate exine. The pistillate flowers are ovoid with three broad, imbricate sepals and as many valvate petals. There may be up to nine tooth-like staminodes or none at all; gynoecium uniocular and ovoid with broad, pendulous stigmas. The

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

is ellipsoidal to subglobose, maturing to black, with a thin endocarp, carrying one

seed A seed is an embryonic plant enclosed in a protective outer covering, along with a food reserve. The formation of the seed is a part of the process of reproduction in seed plants, the spermatophytes, including the gymnosperm and angiospe ...

. The seed is round with homogeneous endosperm and a basal embryo.

Distribution and habitat

They are restricted to

Mauritius Mauritius ( ; french: Maurice, link=no ; mfe, label=Mauritian Creole, Moris ), officially the Republic of Mauritius, is an island nation in the Indian Ocean about off the southeast coast of the African continent, east of Madagascar. It incl ...

and

Réunion Réunion (; french: La Réunion, ; previously ''Île Bourbon''; rcf, label= Reunionese Creole, La Rényon) is an island in the Indian Ocean that is an overseas department and region of France. It is located approximately east of the island ...

though the populations have been so disturbed that their

ecology Ecology () is the study of the relationships between living organisms, including humans, and their physical environment. Ecology considers organisms at the individual, population, community, ecosystem, and biosphere level. Ecology overlaps wi ...

is poorly known. Because the islands were volcanically formed, the palms are often found on sloping terrain from sea level to 1350 meters. They are cultivated around the world.

References

External links

International Plant Names IndexNPGS/GRINGBIF portal
{{Taxonbar, from=Q968747 Arecaceae genera Endemic flora of the Mascarene Islands