Johannesteijsmannia

Johannesteijsmannia altifrons

Johannesteijsmannia is a Native to Southeast Asia palm genus. They are easy to recognize by its diamond-shaped, undivided leaves.

• 4.1 Notes and references

Features

The representatives are eye-catching stemless or short-stemmed, reinforced palms. They are several times flourishing and hermaphrodite. The trunk is very short, decumbent or upright. The leaf scars are annular.

The chromosome number is 2n = 34

The leaves are large, undivided and diamond-shaped. You are ribbed fiederförmig. The leaf sheath is initially Roehrig, dried and later breaks down into a fibrous mass. The petiole is pronounced, almost triangular, flattened adaxial in cross section and reinforced along the edges with small, sharp teeth. Very young petioles are hairy. An expanding leaves an adaxial Hastula exists, but disappears during leaf maturity. The Costa stretches almost to the tip, it is more apparent at the lower leaf surface than at the top. The leaf blade is ribbed fiederförmig, and bald, or densely hairy white at the bottom.

Inflorescences

The inflorescences are between the sheets ( interfoliar ). They are short and often partially hidden by dead leaf material. The inflorescence is branched from one to five times. The peduncle is clearly developed, usually curved and hairy. The cover page is Roehrig, somewhat inflated, zweikielig and most densely hairy. The bracts on the peduncle are conspicuous, up to seven in number, cinnamon and initially cream-colored, later. You are Roehrig, inflated and are distich. All bracts and tear on the cover sheet on the side facing the floor and allow so that bends down the inflorescence. The inflorescence axis is shorter than the stem, the side branches are in the axils of small, triangular bracts. You side branches are often closely together. The flower-bearing axes ( Rachillae ) are either very thick, then there are only three to six, or they are very numerous and slender. They carry in a spiral arrangement of small bracts of the flowers. The flowers appear singly or in wrapping to two to four flowers. The flowers are on short hikes or are sitting.

Flowers

The flowers are hermaphroditic, cream colored and very fragrant. The calyx is cup-shaped with three flat, bare, triangular lobes. The crown is divided to two thirds or nearly to the base into three thin or very thick, fleshy, triangular, bald, sometimes dense papillary, valvate corolla lobes. The six stamens are epipetal, have very broad, fleshy filaments that are fused at the base into a ring and are narrowed abruptly to short, very narrow peaks. The anthers are very small, roundish and intrors.

The gynoecium consists of three carpels. They are free of said base and connected to the tips, so that a common, long, slender pen is produced. The scar is punctiform. The ovule is located basally and is anatrop.

The pollen is ellipsoidal, bisymmetrical or slightly asymmetrical. The germ is opening a distal sulcus. The longest axis measures 20-32 microns.

Fruit and seeds

The fruit is round and usually develops from only one of the three carpels. Sometimes also develop two or all three, then the fruit is two - or three-lobed. The epidermis of the fruit dies early in development from, the mesocarp then ruptures and forms thick, korkige, pyramidal warts and is of maroon color. The endocarp is moderately thick and crusty. The seed sits basal, the endosperm is homogeneous, but penetrates into the base mass of the seed coat into the endosperm.

Dissemination and locations

The genus is found only in Southeast Asia. One type is quite widespread and is in Southern Thailand, West Malaysia, found on Sumatra and western Borneo. The other three species are endemics of West Malaysia.

All are plants of the undergrowth of primary rainforests. They seem to be very sensitive to disturbance of the site. In Sarawak Johannesteijsmannia altifrons on the " kerangas " ( heath forest) is limited. In other areas it is less restricted by the location, but avoid wet valley bottoms. Johannesteijsmannia magnifica and Johannesteijsmannia lanceolata grow on hill - slopes, Johannesteijsmannia perakensis on slopes and hilltops. The distribution of the species is disjoint strikingly, the species often missing in appearing suitable forests.

System

The genus Johannesteijsmannia is placed in the subfamily Coryphoideae, Tribe Trachycarpeae, subtribe Livistoninae within the family Arecaceae. The genus is probably monophyletic. Johannesteijsmannia may be the sister group of Licuala or Pholidocarpus.

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

• Johannesteijsmannia altifrons
• Johannesteijsmannia lanceolata
• Johannesteijsmannia magnifica
• Johannesteijsmannia perakensis

Johannesteijsmannia was first described by Harold E. Moore in 1961, the type species is Johannesteijsmannia altifrons, until then as Teysmannia altifrons Rchb.f. & Customs. performed. The genus name honors John Elias Teijsmann (1808-1882), a gardener and botanist at the then Buitenzorg Botanic Garden in Java.

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. 266-268.