Retispatha
Encyclopedia
Retispatha is a rare, monotypic genus
of flowering plant
in the palm
family endemic to Borneo
, where the sole species, Retispatha dumetosa, is known as wi tebu bruang (dialectial: wi tebi bagadap) or "the bear's sugar cane". The name combines Latin
and Greek
words meaning "network" and "spathe", and the species epithet means "bushy". While classified with other rattan
s, they retain only superficial climbing organs; they sprawl and lean but are not true climbers.
is borne on a well-developed and armed petiole, the sheath and rachis also whorled with spines and covered in tomentum. The linear leaflets are regularly arranged with one fold, margins are toothed, and the midrib is prominent.
On flowering, the inflorescence in male plants is branched to three orders, in females to one, rarely two. The prophyll is large, splitting and becoming tattered, and armed with pseudo-whorls of black spines. Peduncular bracts are not present in the genus, the first order branches bear distichous, unarmed tubular bracts with fibrous limbs which subtend or wholly enclose, in the staminate spike, the second order branch system. These are subtended by tubular, membranous bracts, the third order rachillae have similar bracts subtending solitary staminate flower
s.
The staminate flowers are tiny with a tubular calyx divided into three hairy, triangular lobes. The corolla is basally tubular and twice as long as the calyx, divided into three lobes, striate and valvate. There are six stamens with laterally connate filaments and oblong to ovate anthers, dorsifixed towards the base. The pollen
is circular to elliptical and monosulcate; exine reticulate and tectate and irregularly spotted with striate spines; the tiny pistillode is trifid.
In female plants the inflorescence usually features one main branch and the branchlets may grow from the main axil, the branch, or both. The branchlets are subtended by netlike bracts, often enclosing them, each small branch bearing up to 20 pistillate flowers, each flower held in two distinct bracteoles. A sterile staminate flower is usually absent. The pistillate flowers are larger, calyx similar, with six staminodes. The filaments are joined to form a tube, the empty anthers flattened, gynoecium ovular, trioculate and scaly. There are three conspicuous fleshy stigmas, reflexed, with a basally attached ovule. The beaked fruit
is ovoid to pear shaped, covered in reflexed scales, with a thin mesocarp. Each fruit carries one basally attached seed
with a basal embryo
.
s, absent from the montane
and heath
varieties. No local uses have been recorded.
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 Borneo
Borneo
Borneo is the third largest island in the world and is located north of Java Island, Indonesia, at the geographic centre of Maritime Southeast Asia....
, where the sole species, Retispatha dumetosa, is known as wi tebu bruang (dialectial: wi tebi bagadap) or "the bear's sugar cane". The name combines 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...
and 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 meaning "network" and "spathe", and the species epithet means "bushy". While classified with other rattan
Rattan
Rattan is the name for the roughly 600 species of palms in the tribe Calameae, native to tropical regions of Africa, Asia and Australasia.- Structure :...
s, they retain only superficial climbing organs; they sprawl and lean but are not true climbers.
Taxonomy
Despite bearing strong resemblance to members of the Plectocomiinae, in preparing illustrations for the palm survey Genera Palmarum, Marion Sheehan discovered a single sterile, staminate flower among the pistillate members. The absence of such a flower previously obscured its relationship with the Calaminae, which it also closely resembles. This find, despite its rarity, seems to confirm its placement in the Calaminae subtribe.Description
The clustering trunks are extensively armed with spines, 6 - 8 cm wide, closely ringed, with aerial roots at lower leaf nodes. The pinnate 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....
is borne on a well-developed and armed petiole, the sheath and rachis also whorled with spines and covered in tomentum. The linear leaflets are regularly arranged with one fold, margins are toothed, and the midrib is prominent.
On flowering, the inflorescence in male plants is branched to three orders, in females to one, rarely two. The prophyll is large, splitting and becoming tattered, and armed with pseudo-whorls of black spines. Peduncular bracts are not present in the genus, the first order branches bear distichous, unarmed tubular bracts with fibrous limbs which subtend or wholly enclose, in the staminate spike, the second order branch system. These are subtended by tubular, membranous bracts, the third order rachillae have similar bracts subtending solitary staminate flower
Flower
A flower, sometimes known as a bloom or blossom, is the reproductive structure found in flowering plants . The biological function of a flower is to effect reproduction, usually by providing a mechanism for the union of sperm with eggs...
s.
The staminate flowers are tiny with a tubular calyx divided into three hairy, triangular lobes. The corolla is basally tubular and twice as long as the calyx, divided into three lobes, striate and valvate. There are six stamens with laterally connate filaments and oblong to ovate anthers, dorsifixed towards the base. 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 circular to elliptical and monosulcate; exine reticulate and tectate and irregularly spotted with striate spines; the tiny pistillode is trifid.
In female plants the inflorescence usually features one main branch and the branchlets may grow from the main axil, the branch, or both. The branchlets are subtended by netlike bracts, often enclosing them, each small branch bearing up to 20 pistillate flowers, each flower held in two distinct bracteoles. A sterile staminate flower is usually absent. The pistillate flowers are larger, calyx similar, with six staminodes. The filaments are joined to form a tube, the empty anthers flattened, gynoecium ovular, trioculate and scaly. There are three conspicuous fleshy stigmas, reflexed, with a basally attached ovule. The beaked 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 ovoid to pear shaped, covered in reflexed scales, with a thin mesocarp. Each fruit carries one basally attached 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...
with a basal 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
The one species is scattered across Borneo forming dense patches in hills and valleys of Dipterocarp 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, absent from the montane
Montane
In biogeography, montane is the highland area located below the subalpine zone. Montane regions generally have cooler temperatures and often have higher rainfall than the adjacent lowland regions, and are frequently home to distinct communities of plants and animals.The term "montane" means "of the...
and heath
Heath (habitat)
A heath or heathland is a dwarf-shrub habitat found on mainly low quality acidic soils, characterised by open, low growing woody vegetation, often dominated by plants of the Ericaceae. There are some clear differences between heath and moorland...
varieties. No local uses have been recorded.