''Acanthophoenix'' is a genus of

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 ...

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 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), ...

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

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), ...

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 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 ...

.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: 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 for "thorn" and "

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

".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 a principal appendage of the plant stem, 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 leav ...

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 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 ...

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 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 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 most types of flowers of seed plants for the purpose of sexual reproduction. It consists of pollen grains (highly reduced Gametophyte#Heterospory, microgametophytes), which produce male gametes (sperm ...

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 (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 ...

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

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 ...

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

Distribution and habitat

They are restricted to

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 ...

and

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 ...

though the populations have been so disturbed that their

ecology Ecology () is the natural science of the relationships among living organisms and their Natural environment, environment. Ecology considers organisms at the individual, population, community (ecology), community, ecosystem, and biosphere lev ...

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.

Species

References

External links

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