Sommieria
Sommieria leucophylla is an endemic plant species in New Guinea from the palm family ( Arecaceae ). It is the only species of the genus Sommieria. This palm is very small and has little or no divided leaves that are dark green on top and on the bottom densely hairy white. The inflorescence has a long stem and is sparsely branched, the fruits are small and carry Korkwarzen. The species grows in the understory of forests, their leaves are used for covering roofs.
- 5.1 Literature
- 5.2 Notes and references
Features
Sommieria leucophylla has petite, cylindrical stems 3-4 cm diameter. The trunk is more than up to three meters high, but may be absent. He looks like that of a small coconut tree. The root surface is light brown to gray and closely occupied with annular leaf scars. In cross section a thin outer bark of less than 1 mm thickness can be seen. Inward follows an inner bark with evenly distributed vascular bundles. In the inner bark level is memorized. The wood is soft, black fibers, as in the closely related genera are missing.
The crown consists of up to 40 sheets. Especially with plants that grow in the deep shade, plenty of dead leaves remain on the plant. The leaves grow long and remain on the plant too long, but exact data are not known to do so. The crown acts as a trap for stray, living in the micro-and macro - decomposers like fungi, arthropods and earthworms and reduce the scattering. When it rains, the nutrients are then washed into the soil to the roots of the palm.
The leaves are 92-180 cm long and 12-30 cm wide. They are entire, and split in two. The two halves of the leaf are usually not divided. More rarely, the upper leaf part is divided into two and the lower blade end are one or two pairs of narrow, pointed segments. The ends of the leaves are pointed to rounded, the apical double edge is serrated. Leaf shape, segmentation and perforation are quite variable. The upper leaf surface is usually dark green, ranging from light to dark green enough. The underside is white, cream or light brown. The petiole 10 to 38.5 cm long, the rachis 40-115 cm.
Hairs
Leaves and inflorescences are hairy. There are two types of hairs: woolly hair and white, amorphous coat. The woolly coat is cream-colored to dark brown and can be found on inflorescences, petioles, leaf sheaths and rarely at the bottom of Blattrhachis. The white, amorphous hair is found on the underside of leaves and is always present. It appears waxy, but does not melt when heated. The coat varies greatly within and between individuals of a population and also varies with the age, by decreasing with increasing age.
Inflorescence
The inflorescence is between the leaves and is single. In its heyday, it is up to 160 cm long. He branches out once, rarely twice. In the young bud of the inflorescence is surrounded by a cream-colored to light brown cover page. There is a paper-like cover page on the inflorescence stalk, which is located at the tip of the stem a few centimeters or less. These two bracteoles tear along, when to stretch the peduncle and its side branches to grow. At this time the flowers are only partially developed. The peduncle is long up to 136 cm.
The inflorescence axis is very short. The side branches are starting at the top of the peduncle. You are schraubig, are round in cross section, which are the lowest sometimes branched. The bracts of the lateral axes are triangular to reniform. Along the side of the axis are the flowers in threes in small pits.
The inflorescence appears from the continue reading three to six months before anthesis. The inflorescences are marked protandrous, self-pollination within an inflorescence is therefore not possible. The pollinators are not known as flower visitors ants were observed in the female flowers are often small insect larvae observed.
Flowers
The triads of flowers consist of a central female and two lateral male flowers. The male flowers are in bud stage cream to light brown, to flower white to cream-colored. They are smaller than the female flowers. The female flowers are not initially visible, but obscured by the male. Only after the fall of the male flowers, the female visible and grow.
The male flowers have a diameter of about 2.5 mm. You have three free sepals, which are arranged like roof tiles. The sepals are semicircular to reniform and cream to light brown. On the outside can sit a thin, brown hair. You are strongly keeled and have at the top, sometimes two or three lobes. The three petals are free, ovate to triangular and cream to brown. The six sheets are disposed in a dust whorl, the anthers are bent inwardly in the bud, sometimes additionally twisted. The ovary - rudiment is columnar and shorter than the stamens.
The female flowers also each have three sepals and petals. Their diameter is 2.5 to 3 mm. The petals are free or fused at the base shortly. They are rounded triangular and cream to light brown. They have two to six tooth-like staminodes. The gynoecium is ovoid, a stylus is not recognizable. There are three standing apical scars. The flowers have no scent.
Fruit and seeds
The fruits are small, round and contain a seed. They are 9-15 x 8-15 mm in size. The petals remain on the fruit obtained, as the scars. The exocarp is initially smooth, soon after fertilization, it dries up and dies. It is dark brown and is broken when the fruit grows. The mesocarp is fleshy and spongy - occupied for fruit ripening with pyramid-shaped to hexagonal Korkwarzen, these are usually bright pink. The pericarp contains tannin cells, vascular bundles with scattered fiber sheaths and Brachysklereiden.
The seeds are spherical, ovoid, or ellipsoidal. You have a flat raphe that runs from the navel to the top of the seed. The umbilicus is narrow and is located at the base of the seed. The endosperm is homogeneous, the embryo sits subbasal. The seeds germinate in three to twelve months.
Distribution and ecology
Sommieria leucophylla is endemic to New Guinea. It occurs only on the belonging to Indonesia western half of the island as well as on Waigeo the only upstream island. The known localities are predominantly on the bird's head peninsula, the northernmost finds come from Mamberamo, the southernmost of Timika. Only the easternmost localities lie almost on papua neuguineischem area. This scattered distribution may be due either to unequal Aufsammlung or at an unknown binding type to the specific site conditions.
The most well-known individuals grow on slopes or on the valley floor. They grow in 5 to 500 m above sea level, mostly on podzol or alluvial soils. The pH is 3.5 to 6.2. The temperature range is 22-28 ° C. The plants grow to about 40 to 85% shaded places, so are plants of the forest undergrowth.
The propagation mechanisms are unknown. The color of the fruit spread forth animal is expected to also spread by gravity over short distances is discussed.
System
Sommieria was traditionally made in the subtribe Iguarininae the tribe Areceae, in the work of John Dransfield and colleagues in 2005 but transferred together with Pelagodoxa in the new tribe Pelagodoxeae.
The describer of the genus as the species is ODOARDO Beccari, the Sommieria leucophylla 1877 described. The genus name honors the botanist Stephen divan. By 1915, he described another two species of the genus, Sommieria elegans and Sommieria affinis. Heatubun (2002) showed in a processing of all known herbarium specimens, that the separation of the genus into three species can not be maintained because all the traditional distinction features serving to exhibit continuous transitions.
Use
Like other types of palm trees that grow in the understory of forests, Sommieria has little economic significance. Traditionally, the leaves are used for thatching. The Arfak area Manokwari used the leaves frequently so as well as for wrapping food. Some palm populations are therefore almost completely defoliated.
A threat to the species is based on the conversion of their plants in oil palm plantations.