Plectocomiopsis

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Plectocomiopsis
Systematics
Class : Bedecktsamer (Magnoliopsida)
Monocots
Commelinids
Order : Palm- like arecales
Family : Palm family (Arecaceae)
Genre : Plectocomiopsis
Scientific name
Plectocomiopsis
Becc.

Plectocomiopsis is a climbing palm genus native to Asia.

features

The representatives are multi-stemmed, high-climbing rattan palms. They are hapaxanth , so they bloom only once in a lifetime, and diocesan . The trunk is often triangular, has long internodes and striking leaf scars. Side branches arise on the basal leaf axils.

The number of chromosomes is unknown (as of 2008).

leaves

The leaves on fully grown, climbing stems are pinnate and have a tendril . The leaf sheath is tubular, rather weakly reinforced to unreinforced. One knee is missing, there is an ochrea . The leaf stalk may be missing, the stalk and lower part of the rachis are deeply furrowed. The upper part and the tendril are regularly covered with backward-facing spines. The leaf consists of a few to numerous leaflets. These are simply folded, lanceolate and with entire margins.

Inflorescences

The inflorescences arise at the same time in the axils of the most distal, often reduced leaves of the stem. They are simple, rarely double branched. The peduncle is short. The cover sheet is roehrig, two-keeled and remains within the leaf sheath of the supporting sheet . Bracts on the peduncle are missing. The inflorescence axis is much longer than the stalk. The bracts on the axis are tubular, stand almost in two lines (distich) and each carry a horizontal or rather hanging side branch of the first order. These have a two-keeled cover sheet and distiche, tubular bracts, each of which has a flower cluster. Only in Plectocomiopsis corneri are the inflorescences branched again and have flowers on the lateral axes of all orders. The flower cluster is monopodial and corresponds to a contracted rachilla .

blossoms

The male flowers are almost spaced apart in groups of up to 32 flowers. Each flower stands in the axilla of a cup-shaped rachilla bract , and it also has a cup-shaped, double- sided bract . The calyx is thick, strongly leathery, tubular with three short lobes. The abaxial side is often covered with scale-like trichomes . The crown is thick, leathery and fused to form a tube over almost its entire length. It is covered with scale-like trichomes. The six stamens are epipetal and are laterally fused together and form a tube, at the end of which there are six short, free stamens with short anthers . The pollen is ellipsoidal and bisymmetrical. The longest axis measures 19 to 34 microns.

The female flowers are seldom individually, but mostly in groups of two to four flowers, each in the axilla of a cup-shaped bractea with a two-keeled bracteole, rarely with a second, then very small bracteole. The chalice is tubular, thick and leathery. It remains on the ripe fruit and enlarges and splits in the process. The crown is also thick and leathery, with three short lobes. The calyx and crown are covered with scale-shaped trichomes. The gynoeceum is egg-shaped to cylindrical, with scales only at the base of the three stigmas when it blooms . The three fruit compartments are incompletely separated, each has an anatropic, basal ovule .

Fruits and seeds

The fruit is usually single-seeded, rarely two-seeded. The flower envelope is retained. At the top there are scar remains. The exocarp is covered with somewhat irregular vertical rows of scales pointing downwards. The mesocarp is thin, the endocarp is undifferentiated. The seed sits basal and usually spherical. The sarcotesta is thick but not juicy. The endosperm is homogeneous.

Distribution and locations

The representatives are located in Southeast Asia: Thailand , Malay Peninsula , Sumatra and Borneo . They mainly grow on disturbed locations of primary forests. The two species Plectocomipsis triquetra and Plectocomiopsis wrayi are restricted to the lowland swamp forests of Borneo and the Malay Peninsula. Plectocomiopsis geminiflora grows in various forest types at up to 1200 m above sea level, while the other two species only occur locally in lowland dipterocarp forests at up to 700 m.

Systematics

The genus Plectocomiopsis Becc. is placed within the family Arecaceae in the subfamily Calamoideae , tribe Calameae . Together with the genera Myrialepis and Plectocomia, it forms the subtribe Plectocomiinae . The relationships between the three genera are unclear. The monophyly of plectocomiopsis has not yet been investigated (as of 2008).

The Royal Botanic Gardens, Kew's World Checklist of Selected Plant Families recognizes the following species:

use

The shoot tips of Plectocomiopsis geminiflora are valued as a vegetable in Borneo, although they are bitter. Other species are considered palatable or poisonous depending on the area.

The trunks are not suitable for use as rattan as they are easily splintered.

supporting 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. 188-190.

Individual evidence

  1. ↑ Rafaël Govaerts (ed.): Plectocomiopsis. In: World Checklist of Selected Plant Families (WCSP) - The Board of Trustees of the Royal Botanic Gardens, Kew . Retrieved November 7, 2014.

Web links