Pogonotium

Pogonotium is a Native to Southeast Asia palm genus.

• 4.1 Notes and references

Features

The representatives are reinforced, slender, single or multi-stemmed palm trees that grow upright or short climber. They are multi- flowering, dioecious getrenntgeschlechtige ( dioecious ) trees. The strain has short internodes.

The chromosome number is unknown.

The leaves are pinnate and bear no tendril. The leaf sheath is Roehrig and densely covered with whorled or scattered the piercing as well as a fur felt. The sheath ends at two upright narrow ears, one on each side of the petiole. Is missing a knee or a lack of skilled. A flagellum is missing as well. The petiole is clearly trained and staffed with backward -looking spines that also reinforced the rachis. The few to very numerous leaflets are linear, easily folded and arranged regularly. Their surface is studded with different bristles and scales. The middle ribs are clearly at the bottom.

Inflorescences

The inflorescences are in leaf axils, but are fused with the internode and the leaf sheath of the next sheet. You stand upright between the two Öhrechen of the liner sheet and are nearly sessile. The female inflorescences are branched twice, the male three times. The cover page includes the inflorescence, is boat-shaped with a flattened beak. It is reinforced or unreinforced and tears in the longitudinal direction along the central adaxial or abaxial line and gives the flowers so freely. The bracts of the inflorescence axis are much smaller than the previous sheet. Your tips are free. In each armpit of the bracts as the cover page is a page axis. The bracts of the first order lateral axes are Roehrig at the base and have triangular branches.

Flowers

The male flowers are single in nearly disticher ( two-line ) arrangement on the branches of second or third order. Each stands in the axil of a small, short -tubular, triangular support sheet and has a zweikielige Brakteole. The cup is in the lower part Roehrig, striped, and terminates in three triangular lobes. The crown is divided almost to the base into three triangular lobes valvate. The six stamens are at the base of Kronlappen, their filaments are fleshy, long and curved at the tip inward. The anthers are oblong, Medifix, arrow-shaped at the base, and latrors. The stamp rudiment is small. The pollen is bisymmetrical and monoporat, wherein the seed is located in a hole of the two short axes of the pollen grain.

The female flowers are in dyads, each is supported by a small, triangular bract. The dyad consists of a female and a sterile male flower and two zweikieligen, cup-shaped Brakteolen. The sterile male flower is often twisted and has clear, flat anthers. The female flowers are larger than the males. The calyx is cup-shaped, striped, the lobes triangular and valvat. The crown tears almost to the base into three triangular, valvate lobes. The six staminodes are epipetal. The gynoecium is incomplete dreifächrig with one ovule per fruit tray. It is egg-shaped and scaly with three scars.

Fruit and seeds

The fruit is one seed, spherical or ovoid and beaked. At the top are scars residues. The exocarp is magenta to maroon shed covered with vertical rows of downward. The mesocarp is used for fruit ripening thin and dry, a endocarp is not differentiated. The seed consists of basal, his sarcotesta is thick and sweet tasting. The endosperm is homogeneous, the embryo is located basally.

Dissemination and locations

One species is found on the Malay Peninsula and Borneo, the other two only in Borneo. On Borneo, all three species occur in small populations on podsolierten soils on Hügelgraten in about 700 to 1000 m above sea level. This is the transition zone between lowland and mountain rain forest. They also occur in the Kerangas, heath forests. On the Malay Peninsula Pogonotium ursinum grows in dipterocarp forests.

System

The genus Pogonotium is placed in the subfamily Calamoideae, Tribe and subtribe Calameae Calaminae within the family Arecaceae. Within the subtribe it forms with Ceratolobus and Daemonorops a clade. The monophyly of the genus has not been studied so far (as of 2008 ).

In the World Checklist of Selected Plant Families of the Royal Botanic Gardens, Kew, the following species and hybrids are recognized:

• Pogonotium divaricatum
• Pogonotium moorei
• Pogonotium ursinum

Documents

• John Dransfield, Natalie W. Uhl, Conny B. Asmussen, William J. Baker, Madeline M. Harley, Carl E. Lewis: Genera palmarum. The Evolution and Classification of Palms. Second edition, Royal Botanic Gardens, Kew 2008, ISBN 978-1-84246-182-2, pp. 206-207.