Polyandrococos
Encyclopedia
Polyandrococos is a monotypic genus
of flowering plant
in the palm
family endemic to Brazil
, where it is known as buri palm. The name combines the Greek
words for "many" and "anther" with the name of another palm genus Cocos
, and the epithet is Latin
for "bearlike", referring to the hairy tomentum
.
bases. The sheath is tubular, splitting adaxially, striate, and covered in white and brown tomentum. The petiole
is short, deeply channeled, flattened below, with armed margins and similar tomentum; the rachis
is slightly arched, leaflets regular or grouped, in one or several planes with one fold. The undersides are glaucous, the apex is irregularly bifid, the midrib is prominent and the veinlets are evident.
The inflorescence
is a pendulous, solitary, interfoliar spike, unbranched, with an elongated peduncle and a tubular prophyll. The prophyll is two-keeled, short and fibrous and is much smaller than the single peduncular bract, which is deeply grooved with a long beak. The lower half of the length of the rachis is covered in triads while the top has pairs of staminate flowers which shed early, leaving the inflorescence tip bare at antithesis. The bracts around the triads are pointed and ovate; those around the pairs have longer points. The bracts are adnate to the rachis and adjacent bracts forming depressions around the pairs; the bracteoles are inconspicuous.
The staminate flowers are long and asymmetrical with three linear, triangular sepal
s, basally connate and adnate to the receptacle. They have three pointed, obovoid petal
s, which are elongated, valvate, and longer, wider and thicker than the sepals. The stamen
s are numerous, from 60 to 100, irregularly inserted, with cylindrical, elongated, flexible filaments which are bent and twisted, occasionally joined, apiculate, and dorsifixed a third of their length. The pollen
is elliptic and monosulcate with finely reticulate, tectate exine.
The pistillate are smaller, the three distinct sepals are ovate, broadly imbricate, with pointed tips, the three petals are similar but with longer tips. The staminodes are united in an irregular ring, the gynoecium is triocular, triovulate with short trifid stigmas and laterally attached ovules. The fruit
is egg-shaped, with three pores, green to yellow, carrying a single seed
. The epicarp is smooth, the mesocarp is fleshy and fibrous and the endocarp is thick and bony. The seed is basally attacthed and beaked with a shallowly ruminate endosperm and a subbasal embryo
.
s.
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 endemic to Brazil
Brazil
Brazil , officially the Federative Republic of Brazil , is the largest country in South America. It is the world's fifth largest country, both by geographical area and by population with over 192 million people...
, where it is known as buri palm. The name combines the 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 for "many" and "anther" with the name of another palm genus Cocos
Coconut
The coconut palm, Cocos nucifera, is a member of the family Arecaceae . It is the only accepted species in the genus Cocos. The term coconut can refer to the entire coconut palm, the seed, or the fruit, which is not a botanical nut. The spelling cocoanut is an old-fashioned form of the word...
, and the epithet is Latin
Latin
Latin is an Italic language originally spoken in Latium and Ancient Rome. It, along with most European languages, is a descendant of the ancient Proto-Indo-European language. Although it is considered a dead language, a number of scholars and members of the Christian clergy speak it fluently, and...
for "bearlike", referring to the hairy tomentum
Tomentum
Tomentum may refer to the following:*In botany, a covering of closely matted or fine hairs on plant leaves. *A network of minute blood vessels in the brain.* Tomentum in zoology are a short, soft pubescence...
.
Description
The trunks are rough and solitary natured, and reach over 10 m at 20 cm wide, usually covered in old leafLeaf
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....
bases. The sheath is tubular, splitting adaxially, striate, and covered in white and brown tomentum. The 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 short, deeply channeled, flattened below, with armed margins and similar tomentum; the rachis
Rachis
Rachis is a biological term for a main axis or "shaft".-In zoology:In vertebrates a rachis can refer to the series of articulated vertebrae, which encase the spinal cord. In this case the rachis usually form the supporting axis of the body and is then called the spine or vertebral column...
is slightly arched, leaflets regular or grouped, in one or several planes with one fold. The undersides are glaucous, the apex is irregularly bifid, the midrib is prominent and the veinlets are evident.
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...
is a pendulous, solitary, interfoliar spike, unbranched, with an elongated peduncle and a tubular prophyll. The prophyll is two-keeled, short and fibrous and is much smaller than the single peduncular bract, which is deeply grooved with a long beak. The lower half of the length of the rachis is covered in triads while the top has pairs of staminate flowers which shed early, leaving the inflorescence tip bare at antithesis. The bracts around the triads are pointed and ovate; those around the pairs have longer points. The bracts are adnate to the rachis and adjacent bracts forming depressions around the pairs; the bracteoles are inconspicuous.
The staminate flowers are long and asymmetrical with three linear, triangular sepal
Sepal
A sepal is a part of the flower of angiosperms . Collectively the sepals form the calyx, which is the outermost whorl of parts that form a flower. Usually green, sepals have the typical function of protecting the petals when the flower is in bud...
s, basally connate and adnate to the receptacle. They have three pointed, obovoid petal
Petal
Petals are modified leaves that surround the reproductive parts of flowers. They often are brightly colored or unusually shaped to attract pollinators. Together, all of the petals of a flower are called a corolla. Petals are usually accompanied by another set of special leaves called sepals lying...
s, which are elongated, valvate, and longer, wider and thicker than the sepals. The stamen
Stamen
The stamen is the pollen producing reproductive organ of a flower...
s are numerous, from 60 to 100, irregularly inserted, with cylindrical, elongated, flexible filaments which are bent and twisted, occasionally joined, apiculate, and dorsifixed a third of their length. The pollen
Pollen
Pollen is a fine to coarse powder containing the microgametophytes of seed plants, which produce the male gametes . Pollen grains have a hard coat that protects the sperm cells during the process of their movement from the stamens to the pistil of flowering plants or from the male cone to the...
is elliptic and monosulcate with finely reticulate, tectate exine.
The pistillate are smaller, the three distinct sepals are ovate, broadly imbricate, with pointed tips, the three petals are similar but with longer tips. The staminodes are united in an irregular ring, the gynoecium is triocular, triovulate with short trifid stigmas and laterally attached ovules. The 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,...
is egg-shaped, with three pores, green to yellow, carrying a single 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...
. The epicarp is smooth, the mesocarp is fleshy and fibrous and the endocarp is thick and bony. The seed is basally attacthed and beaked with a shallowly ruminate endosperm and a subbasal embryo
Embryo
An embryo is a multicellular diploid eukaryote in its earliest stage of development, from the time of first cell division until birth, hatching, or germination...
.
Distribution and habitat
They are limited to east-central Brazil where they grow in gallery forest and open plains up to the Atlantic coastal forestForest
A forest, also referred to as a wood or the woods, is an area with a high density of trees. As with cities, depending where you are in the world, what is considered a forest may vary significantly in size and have various classification according to how and what of the forest is composed...
s.