''Pogonotium'' was a

dioecious Dioecy (; ; adj. dioecious , ) is a characteristic of a species, meaning that it has distinct individual organisms (unisexual) that produce male or female gametes, either directly (in animals) or indirectly (in seed plants). Dioecious reproductio ...

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

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 ...

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 * Several other plants known as "palm" Palm or Palms may also refer to: Music * Palm (ba ...

family found in

Malaysia Malaysia ( ; ) is a country in Southeast Asia. The federation, federal constitutional monarchy consists of States and federal territories of Malaysia, thirteen states and three federal territories, separated by the South China Sea into two r ...

and

Borneo Borneo (; id, Kalimantan) is the third-largest island in the world and the largest in Asia. At the geographic centre of Maritime Southeast Asia, in relation to major Indonesian islands, it is located north of Java, west of Sulawesi, and eas ...

. Its species are now included within the genus ''

Calamus Calamus may refer to: Botany and zoology * ''Calamus'' (fish), a genus of fish in the family Sparidae * ''Calamus'' (palm), a genus of rattan palms * Calamus, the hollow shaft of a feather, also known as the quill * '' Acorus calamus'', the swe ...

''. Its close relatives are climbing

rattan Rattan, also spelled ratan, is the name for roughly 600 species of Old World climbing palms belonging to subfamily Calamoideae. The greatest diversity of rattan palm species and genera are in the closed-canopy old-growth tropical forests of ...

s and while partially armed with climbing apparatus, its habit is sprawling and leaning but not effective climbing. The reduced inflorescence nestled between the auricles is unusual and distinguishes it from similar relatives like ''

'', ''

Daemonorops ''Daemonorops'' was a genus of rattan palms in the family Arecaceae. Its species are now included within the genus ''Calamus''. Species found primarily in the tropics and subtropics of southeastern Asia with a few species extending into souther ...

'' and '' Ceratolobus''.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. / The name is

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 ...

meaning "bearded".Riffle, Robert L. and Craft, Paul (2003) ''An Encyclopedia of Cultivated Palms''. Portland: Timber Press. /

Description

The trunks are both solitary and clustering with short internodes, usually covered in spiny, persistent leaf sheaths. The pinnate

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 ...

has a tubular sheath with whorls and scatters of spines and hairy, brown tomentum, the sheath ending in a narrow, armed auricle on each side of the petiole. The petiole is abaxially rounded, adaxially flattened, hairy, and equipped with grapnel spines. The rachis is similarly armed, the leaflets widely spaced to crowded, linear, with one fold, and covered in bristles and scales; the midrib is adaxially prominent, the transverse veinlets are short yet conspicuous. The

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 ...

, though axillary, is adnate to the internode and sheath of the following leaf, emerging erect between the auricles of the subtending leaf. In pistillate members it is branched to two orders, staminate to three; in both, a boat shaped, beak-ended prophyll encloses it. The prophyll may or may nor be armed and eventually develops a longitudinal split, exposing the

flowers 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 ...

. The rachis bracts are small with free tips, the bracts on the first-order branches are tubular towards the base with triangular limbs. The staminate flowers are solitary borne, on second and third order branches, subtended by a tiny, tubular, triangular bract and a two keeled bracteole. The tubular calyx is proximally striate, divided into three triangular lobes; the corolla is divided nearly to the base into three lobes. The six stamen are borne at the base of the corolla with fleshy, elongated filaments, inflexed at the tip, with oblong, medifixed anthers. The pollen is elliptic, diporate with rugulate to reticulate, tectate exine. The larger pistillate flowers are borne in dyads, similarly subtended by a triangular bract, and accompanied by a sterile staminate flower and two, two keeled bracteoles. The sterile

staminate The stamen (plural ''stamina'' or ''stamens'') is the pollen-producing reproductive organ of a flower. Collectively the stamens form the androecium., p. 10 Morphology and terminology A stamen typically consists of a stalk called the filam ...

flower is similar to the fertile but is slightly contorted with empty

anthers The stamen (plural ''stamina'' or ''stamens'') is the pollen-producing reproductive organ of a flower. Collectively the stamens form the androecium., p. 10 Morphology and terminology A stamen typically consists of a stalk called the filam ...

. The

pistillate Gynoecium (; ) is most commonly used as a collective term for the parts of a flower that produce ovules and ultimately develop into the fruit and seeds. The gynoecium is the innermost whorl of a flower; it consists of (one or more) ''pistils'' ...

has a

striate In geology, a striation is a groove, created by a geological process, on the surface of a rock or a mineral. In structural geology, striations are linear furrows, or linear marks, generated from fault movement. The striation's direction revea ...

, cup shaped calyx with triangular, valvate lobes, and the corolla splits to the base into similar triangular segments. There are six epipetalous staminodes, with triocular, triovulate, scaly, ovoid

gynoecium Gynoecium (; ) is most commonly used as a collective term for the parts of a flower that produce ovules and ultimately develop into the fruit and seeds. The gynoecium is the innermost whorl of a flower; it consists of (one or more) ''pistils'' ...

and three fleshy, divergent, rugose stigmas, attached at the base. 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 globose or ovoid, beaked, with apical stigmatic remains and covered in vertical rows or magenta to brown scales. The single

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 ...

has a basal

embryo An embryo is an initial stage of development of a multicellular organism. In organisms that reproduce sexually, embryonic development is the part of the life cycle that begins just after fertilization of the female egg cell by the male spe ...

, a thick

sarcotesta The sarcotesta is a fleshy seedcoat, a type of testa. Examples of seeds with a sarcotesta are pomegranate and some cycad seeds. The sarcotesta of pomegranate seeds consists of epidermal cells derived from the integument, and there are no aril ...

and a sweet, homogeneous

endosperm The endosperm is a tissue produced inside the seeds of most of the flowering plants following double fertilization. It is triploid (meaning three chromosome sets per nucleus) in most species, which may be auxin-driven. It surrounds the embryo and ...

Distribution and habitat

These are a

tropical The tropics are the regions of Earth surrounding the Equator. They are defined in latitude by the Tropic of Cancer in the Northern Hemisphere at N and the Tropic of Capricorn in the Southern Hemisphere at S. The tropics are also referred to ...

plant, ''P. divaricatum'' and ''P. moorei'' are sometimes found high on

Bornean Borean (also Boreal or Boralean)http://ehl.santafe.edu/EhlforWeb.pdf is a hypothetical linguistic macrofamily that encompasses almost all language families worldwide except those native to the Americas, Africa, Oceania, and the Andaman Islands. ...

ridge tops from 700 to 1000 m in podsolized soils or in

heath A heath () is a shrubland habitat found mainly on free-draining infertile, acidic soils and characterised by open, low-growing woody vegetation. Moorland is generally related to high-ground heaths with—especially in Great Britain—a cooler ...

forests called "kerangas". ''P. ursinum'' is confined to the Malaysian peninsula.

References

External links

GBIF portalFairchild Guide to Palms: ''Pogonotium''
{{Taxonbar, from=Q143608 Calamoideae Dioecious plants Arecaceae genera