Salacca

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Salacca
Salak palm (Salacca zalacca) plantation on Java

Plantation of Salak ( Salacca zalacca ) on Java

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

Salacca is a genus of plants within the palm family Arecaceae. The 20 or so species are common in Southeast Asia. The salak palm ( Salacca zalacca ) is grown forits fruits. There are almost stemless palm trees that form thickets.

features

Habit and leaves of Salacca magnifica

The Salacca species usually have no trunk, form several crowns, are thorny and dioecious ( dioecious ).

The trunk is located underground and lying, less often above ground and upright. Usually it is covered by the leaf bases. The internodes are short, they often form numerous adventitious roots .

The number of chromosomes is 2n = 28.

leaves

The leaves are small to robust, pinnate or whole or in two parts. The leaf sheath tears lengthways opposite the petiole. The lowest part is unreinforced, the rest is scattered or densely covered with spines . The petiole is very variably covered with spines and scales. The rachis is reinforced like the petiole, albeit less. The leaflets of pinnate species are simply folded with the exception of the terminal ones. They are straight or sigmoidal, pointed at the end, less often lobed. They can be reinforced with short spines to varying degrees along the central ribs and on the leaf margins. The terminal pair of leaflets is composed. With whole or two-part leaves, the end of the leaf is deeply bilobed to almost entire . The underside of the leaf is often very hairy floury. The central ribs stand out clearly on the underside of the leaf.

Inflorescences

The inflorescences are in the leaf axils , and first by the leaf sheath their support sheet wrapped. This tears open along the center line and the inflorescence comes out through the opening. It is usually short, sometimes spiked , but mostly branched one or two times . Sometimes the inflorescence is hidden in the detritus . Very rarely it is whip-shaped with a point that turns into a vegetative axis, takes root and grows into an independent plant. Male inflorescences are usually branched one order higher than female ones. The inflorescence stalk is usually short, the cover sheet little noticeable and often hidden in the leaf sheath of the bract. It is roehrig, two-keeled. There are several bracts on the peduncle, these are tubular at the base. The inflorescence axis is usually longer than the stem, their bracts are similar to those on the stem. The lateral axes are cylindrical, kitten-like and can be hidden in the bract or free. The bracts of the flowers form a spiral and can be fused together.

blossoms

The male flowers stand in pairs (in dyads) and have two small bracts that are sometimes split or fused together. The calyx is tubular and three-lobed, sometimes split almost to the base. The crown has a short, stem-like base and a long tube that ends in three triangular lobes. The six stamens are at the end of the corolla tube, their filaments are short and the anthers are rounded to oblong. The rudiment of the stamp is very small or missing. The pollen is spherical or flattened at the poles. The germ opening (aperture) is a meridional zonasulcus (ring-shaped germ fold), sometimes not completely ring-shaped. The longest axis is 22 to 34 micrometers long.

The female flowers are solitary or in dyads with a sterile male flower. This resembles the fertile, but the anthers remain empty. The calyx is tubular at the base and has three triangular, longitudinally furrowed lobes. The crown is similar with three triangular, flap-like lobes. There are six staminodes that start at the entrance to the corolla tube. The stamens are mostly elongated, the anthers are arrow-shaped and empty. The gynoeceum consists of three compartments, each with an ovule, and is filled with flat, smooth or pointed scales. The three fleshy stigmas are bent back to the flower. The compartments are incompletely divided, the ovules are at the base and are anatropic.

Fruit of Salacca zalacca

Fruits and seeds

The fruits usually contain three seeds, rarely one or two. They are spherical to pear-shaped or ellipsoidal. The scar remnant is apical . The exocarp is covered with slightly irregular, vertical rows of scales, the tips of the scales are pointed or smooth. The mesocarp is very thin at maturity, the endocarp is not differentiated. The seeds are basal and form a third or a half of a ball, depending on the number of seeds per fruit. Your sarcotesta is very thick, sour or sweet, the inner seed membrane is very thin. The endosperm is homogeneous. The embryo is basal.

Distribution and locations

The area of the genus Salacca extends from Myanmar and Indochina south and east to Borneo, Java and the Philippines. The salak palm is originally native to Java and Sumatra and was introduced to the Malay Peninsula, Borneo, Celebes, the Moluccas and Bali. The greatest biodiversity can be found on the Malay Peninsula and Borneo.

The species are plants of the undergrowth of primary tropical rainforests. Because they are valued as suppliers of fruit and timber, they are often left standing when clearing. Many of the species grow mainly in swampy valley floors, where they form thorny, impenetrable thickets. Other species tend to grow on hill slopes or on knolls. Salacca rupicola grows on limestone cliffs.

Systematics and distribution

The generic name Salacca is the Latinized form of the Malay name salak . The genus Salacca is placed within the family Arecaceae in the subfamily Calamoideae , tribe Calameae . Here it forms the Subtribus Salaccinae together with its sister genus Eleiodoxa .

Salacca Reinw. is so far a monophyletic group, although the species Salacca secunda , which is known to be problematic , has the characteristics of Salacca and those of Eleiodoxa , has not yet been investigated molecularly.

The genus Salacca is widespread from the eastern Himalayas through south-central China to western Malesia.

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

use

The salak palm ( Salacca zalacca ) is grown in large parts of Southeast Asia for its tasty fruits. The fruits of other types are also eaten, but are sometimes very acidic.

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. 172-175.

Individual evidence

  1. ↑ a b c Rafaël Govaerts (Ed.): Salacca. In: World Checklist of Selected Plant Families (WCSP) - The Board of Trustees of the Royal Botanic Gardens, Kew . Retrieved August 2, 2018.

Web links

  • Salacca on the homepage of the Fairchild Tropical Botanic Garden