Calamus (palm)

Calamus gibbsianus

Calamus is a native to Africa and Asia palm genus. There are often climbing Rattanpalmen. It is next to some other genera, the main supplier of rattan. With 374 species, it is the most species-rich genus of the palm family.

• 4.1 Notes and references

Features

The representatives are highly variable. Most species are climbing palms, some are stemless ( acauleszent ) or upright. They grow single-stemmed or multi-stemmed. They are several times flourishing and dioecious getrenntgeschlechtig ( dioecious ). The strain has short or long internodes. Runners arise strictly axillary.

The chromosome number is 2n = 26

The leaves are pinnate, rarely two parts ( bifid ). Sometimes they have a terminal tendril. The sheaths rip open at the acauleszenten species. In free area, they are usually densely armed with scattered or whorled the piercing. The type Calamus polystachys the spines are entangled and so form galleries that are inhabited by ants. There is often a Indument to the vaginal surface. A Ochrea happens frequently. This can be swollen in some species and host ants. A knee is found in most types of climbing.

Species lacking a tendril, often possess a flagellum: a whip -like climbing aid, which emerged from a sterile inflorescence.

A petiole may be absent or be well trained. He is armed differently. The rachis is often occupied with remotely located groups of backward spines. The tendril is, if present, also occupied with backward spines.

The few to numerous leaflets are simply folded, entire ( hard nut only at Calamus caryotoides ), linear to lanceolate or rhombic. The two terminal leaflets can be fused together at their inner edges. The leaflets are different occupied with hairs, bristles, spines and scales.

Inflorescences

The inflorescences are axillary, but are fused with the internode and the leaf sheath of the next sheet. Male and female inflorescences similar, however, the male usually branched into three orders, the female in two. The inflorescences are often whip-like, very rarely can beat them at their peak roots to form new vegetative shoots. A peduncle lacking or may be present, sometimes it is very long. It is reinforced upright or inverted and different. The cover sheet is usually unremarkable, zweikielig, Roehrig, scheidig closely fitting, not reinforced or unreinforced differently. Rarely it is inflated, securities or leathery. The bracts of the inflorescence axis similar to the previous sheet. They are closely related, rarely removed. You are armed differently, mostly Roehrig and even then remain Roehrig, if they tear. In the armpit every high leaf springs from a side branch of the first order or Teilinfloreszenz. This is often grown together with a piece of the inflorescence axis, rarely breaks through the bract by. The first-order lateral axis carries a zweikieliges, röhriges cover sheet and nearly double row ( subdistich ) standing -tube bracts that are reinforced or unreinforced different. In the armpits are the second order, which is a piece are usually grown with the lateral axis of the first order lateral axes. The flower-bearing axes ( Rachillae ) are structured very differently within the genus. You can be expansive and very short and crowded. They usually wear a basal, zweikieliges cover page and showy, usually distiche, tubed bracts triangular peaks that are different or not reinforced or unreinforced. Very rarely, the bracts are crowded and spirally. In the male inflorescences a bract carrying a single male flower with a Brakteole, in the female inflorescences a triad of two lateral female and a central sterile male flower.

Flowers

The male flowers are symmetrical. The cup is three-lobed at the base Roehrig, at the top. The crown is usually longer than the calyx and divided into three valvate lobes, with the exception of the base -tube. There are six stamens present, only at Calamus ornatus there are twelve. They stand at the mouth of the corolla tube. The filaments are often fleshy, sometimes abruptly narrowed. The anther are Medifix, short to long and latrors or intrors. The stamp rudiment is small or even clearly present. The pollen is ellipsoidal, bisymmetrical and has equatorial lying disulcate seed openings. The sterile male flowers resemble the fertile, only their anthers are empty.

The female flowers are usually larger than the male. The cup is Roehrig and weak three-lobed. The crown is hardly longer than the calyx. The six staminodes are epipetal, the filaments are free or form a short ring, the anthers are empty. The gynoecium consists of three carpels with one ovule. It is spherical to ellipsoidal and occupied with downward facing scales. The three stigmas are apical, fleshy, recurved and sometimes stand at a beak. The compartments are incomplete. The ovules are basal and are anatrop.

Fruit and seeds

The fruit is usually one seed, rarely two or three seeds. The scars radicals apically. The exocarp is busy with regular rows of backward shed. The mesocarp is the fruit ripening usually thin, a endocarp is not differentiated. The seed has a thick, sweet, sour or astringent -tasting sarcotesta. The inner part of the seed is round, grooved, winged angular or sharp. The endosperm is homogeneous or ruminat. The embryo is basal or lateral.

Dissemination and locations

The genus has a distribution paläotropische: A species occurs in the humid tropics of Africa. The more complex ranges from southern India and Ceylon Burma and southern China through the Malay Archipelago to Queensland in Australia and Fiji. The greatest diversity of species they reached the territory of the Sunda Islands, especially on Borneo. A second Vielfältigkeitszentrum located on New Guinea.

The ecological requirements are very different. However, few species occur on seasonally dry places, such as in monsoon forests, and in semi-arid regions lacking the genre completely. Some species such as Calamus erinaceus occur among mangrove - like conditions. Some species have very narrow ecological requirements, such as sandstone or ultrabasic rock as a base. Calamus species occur from sea level to over 3000 m before ( so Calamus gibbsianus at Kinabalu ).

System

The genus Calamus is placed in the subfamily Calamoideae, Tribe and subtribe Calameae Calaminae within the family Arecaceae. The genus is almost certainly not monophyletic, the other genera of the subtribe come to lie within the genus molecular genetic According Kladogrammen. The Calaminae decompose accordingly into three major clades. The first clade includes part of Calamus species and the genus Retispatha. The remaining three genera of the subtribe are the sister group of the other Calamus species.

The genus includes about 374 species Calamus. A list of species found in the World Checklist of Selected Plant Families of the Royal Botanic Gardens, Kew.

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. 191-197.