Wallaceodoxa raja-ampat
| Wallaceodoxa raja-ampat | ||||||||||||
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| Systematics | ||||||||||||
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| Scientific name of the genus | ||||||||||||
| Wallaceodoxa | ||||||||||||
| Heatubun & WJBaker | ||||||||||||
| Scientific name of the species | ||||||||||||
| Wallaceodoxa raja-ampat | ||||||||||||
| Heatubun & WJBaker |
Wallaceodoxa raja-ampat is a palm species nativeto the Raja Ampat islands off New Guinea , it is the only representative of thegenus Wallaceodoxa, which is monotypical . It is named after the English naturalist Alfred Russel Wallace (1823–1913).
features
Characteristics of the genus
Wallaceodoxa is a moderately robust, solitary, unreinforced, tree-shaped palm. It is single-sexed ( monoecious ) and blooming several times (pleonanth). The trunk is upright, roughly fissured, whitish brown, the nodes are inconspicuous.
leaves
The leaves are pinnate, drooping, the crown forms a hemisphere. The leaf sheaths are Roehrig and a distinct crown shaft. The sheaths are adaxially glabrous with the exception of scattered patches of white flaky indument . Abaxially there is a thick, white, woolly, falling out indument, which consists of very fine, translucent fibers with a smaller proportion of similar brown fibers. In between there are numerous large, brown-black twisted hairs. The petiole is long, slender, furrowed adaxially, rounded abaxially and covered with a dense indument that resembles that of the leaf sheaths. The rachis is slender, arched and forms a furrow on the top and is rounded abaxially. The indument is similar to that of the leaf sheath, only that the brown-black twisted hairs are more numerous. The leaflets are arranged regularly, almost opposite to alternating. They are hanging. They start on the adaxial surface of the rachis, at the edge of the furrow. They form an acute angle and are simply folded, with an inconspicuous central rib. They are green, adaxially paler, abaxially darker, and glaucous and paper-like. The basal leaflets are linear to lanceolate or slightly sigmoid. The tips are slightly premors. The middle leaflets are elongated, somewhat lanceolate, the ends slightly premorsal. The apical leaflets are paired or single, the tips are truncated and unevenly premorsal or serrated.
inflorescence
The inflorescence is under the foliage leaves (infrafoliar), it is proterandric and up to three-fold (possibly up to four-fold). The peduncle is long, rather flat and slightly elliptical in cross section. It is shorter than the inflorescence axis . It is light green to cream in color with a dense, light to dark brown indument. The cover sheet is balding, lanceolate, two-keeled, paper and cream-colored to light green. It completely encloses the inflorescence, tears open lengthways as the inflorescence unfolds and falls off before the male flowers bloom. The first bract on the peduncle is bald, elongated, paper, cream-colored to light green, with dense woolly hairs scattered on the surface. The remaining bracts are reduced to inconspicuous, horizontal, scar-like pits. The inflorescence axis is light green to cream colored. The most basal side branch of the first order is relatively long. It branches out to some second-order side branches and then to the flower-bearing side branches (rachillae). The first-order side branches are far apart. The rachillae are numerous, fleshy, slightly curved near the tip and hairless. The flower triads are closely lined up.
blossoms
The male flowers are small to medium-sized, elongated, bullet-shaped in the bud, and symmetrical. The color is whitish-cream to greenish-white. The three sepals are free, strongly imbricated and rounded. The three petals are valvate , connected at the base, elliptical with a slightly rounded tip. They are thick and fleshy, slightly striped. The color is light green to cream. The stamens are numerous (58 to 64), variable in length. The filaments are awl-shaped, much longer than the anthers, and white to cream in color. The anthers are arrow-shaped, latrors, and cream-colored. The pistillodium (sterile pistil ) is shorter than the stamens, irregularly ellipsoidal, lobed and cream-colored to dark brown.
The female flower is slightly smaller than the male. It is ellipsoidal, light green to cream-colored and has a protruding scar to the anthesis . The three sepals are strongly imbricated, keeled, rounded and slightly asymmetrical. They are thickened at the base. The three petals are strongly imbricated, elliptical, slightly striped. The few staminodes are inconspicuous, membranous, triangular and cream-colored to light brown. The gynoeceum is ellipsoidal, light green to cream in color. The scar is in three parts and white to the anthesis. The ovule sits basal.
fruit
The fruit is ellipsoidal, the black remnants of stigma and the flower cover remain on the fruit when it is ripe. The exocarp is smooth, shiny, and thin. It is light green at first and turns yellow, orange to red when ripe. The mesocarp is fibrous, fleshy, mucous and tannic. The fibers are delicate to large. The endocarp is surrounded by sclerified basic tissue. The endocarp itself is very thin, cartilaginous, circular in cross section, without any pits or angles. It is straw-colored and has numerous flat, adherent fibers.
The seed is broadly ellipsoidal, without pits or angles, in cross section it is round. The umbilicus ( hilum ) is elliptical, elongated and extends from the base to the tip of the seed. Anostomose the raphenous branches. The endosperm is deeply ruminate. The embryo is basal and white.
Features of the species
Wallaceodoxa raja-amput is a solitary palm with a trunk up to 30 m high. The trunk diameter is 9-30 cm. The internodes have inconspicuous leaf scars. The trunk color is whitish-brown. The crown consists of 11–19 leaves. The leaves are 275-410 cm long including the petiole. The tubular leaf sheath is 76-115 cm long and 16-30 cm wide, narrowing to 10 cm. The crown shaft is 100-150 cm long. The petiole is 28-50 cm long, 2.5-3.5 cm wide and 1-1.5 cm thick at the base. There are 50-85 leaflets on each side of the rhachis. The basal leaflets are 41-60 cm long and 9.5-2.5 cm wide, the middle ones are 70-114 cm long and 1-4.5 cm wide, the apical leaflets are 32-40 cm long and 0.5 -1.5 cm wide.
The inflorescence is 50-100 cm long and 75-80 cm wide at the anthesis. The peduncle is 15-20 cm long and 4-6 cm thick. The cover sheet is 50-60x7-12 cm, the cover sheet is similar. There are up to 27 first-order side branches (including the terminal rachilla). The rachillae are numerous, 11-18 cm long, on them are 12-15 flower triads per 5 cm rachilla length.
The male flowers are 7-7.5x2.5-4 mm in size shortly before anthesis and are whitish-cream-colored to greenish-white. The three sepals are free, 3.2-3.5x2.5-3 mm in size. The three petals are connected at the base, 6-6.3x3-3.5 mm in size. The 58-64 stamens are 3.5-5 mm long. The stamens are 2.5-3x0.3-0.4 mm in size and white. The anthers are 2-2.5x0.5-0.75 mm in size. The cream-colored to brown pestillodium is 1-2x0.9-1.2 mm in size and has 2 to 3 lobes that are around 0.5 mm deep and 0.3 mm wide.
Shortly before anthesis, the female flowers are 5-6x3.5-4 mm in size and cream-colored to light green. The sepals are 3.3-5x3.5-7 mm in size, the petals are light green and 5x6 mm in size. The 5-7 staminodes are 0.4-1x0.2-0.3 mm in size. The gynoeceum is 4-4.5x1.5 mm, including the scar, and the ovule is around 1.5x0.8 mm.
The fruit is 17.5-20x10-12 mm in size, initially light green and then turns yellow, orange and red when ripe. The exocarp is around 1 mm thick. The seed is 10-12x9-9.5 mm, the embryo 1.5-2.75x1-1.75 mm.
Spread and endangerment
The species is only known from two islands in the Raja Ampat group of islands west of New Guinea: Waigeo and Gag . Here it grows in the lowland forest over limestone at up to 50 m above sea level. It was mainly found in secondary forests and severely disturbed forests. The occurrence in old gardens is considered a relic occurrence. It often occurs together with Areca macrocalyx , various Calamus and Licuala species as well as Heterospathe elata .
The known population on the island of Gag decreased between 2006 and 2011 from 45 adult, 32 juvenile specimens and 129 seedlings to 28 adult specimens and no juveniles or seedlings. The causes are deforestation by the local population and the expansion of coconut plantations. 75% of the area of Gag belongs to a nickel mine, the rest consists largely of coconut plantations and gardens. The subpopulation on Waigeo is not known until 2011. A first inventory in the city of Waisai showed only 5 adults, 63 juveniles and 378 seedlings on 4 km². Due to the fact that the species is restricted to limestone locations, only a few more specimens are expected on Waigeo. The population here is threatened by the growth of the city of Waisai.
Wallaceodoxa raja-ampat was classified as critically endangered by the first descriptors due to the small area, the decline in area and the small population size .
Systematics
The genus Wallaceodoxa is placed within the family Arecaceae in the subfamily Arecoideae , Tribe Areceae , Subtribus Ptychospermatinae .
The only species in the genus is Wallaceodoxa raja-amput .
The sister group of Wallaceodoxa is the monotypical genus Adonidia .
The genus is named after the English naturalist and explorer Alfred Russel Wallace . He visited Waigeo Island in 1860. The name was given in memory of the 100th anniversary of Wallace's death on November 7, 1913. The suffix -doxa comes from ancient Greek, from which the name "In honor of Wallace" results.
The species was discovered by Charlie D. Heatubun in 2006. Due to its characteristics, it could easily be assigned to the subtribe Ptychospermatinae, but none of the genera. Only the molecular genetic study by Elodie Alapetite was able to show in 2014 that this species and three others are best described in a monotypic genus. The first description of species and genus was made in 2014 by Heatubun and Baker.
This classification as a separate genus was followed by Dransfield and Baker 2016 in their revised family classification of the palms.
use
The trunk is used as a floor covering. The fruits are chewed as a betel nut substitute.
supporting documents
- Charlie D. Heatubun, Scott Zona, William J. Baker: Three new genera of arecoid palm (Arecaceae) from eastern Malesia . Kew Bulletin 2014, Volume 69, 9525, doi: 10.1007 / S12225-014-9525-X (characteristics, distribution and exposure)
Individual evidence
- ^ A b William J. Baker, John Dransfield: Beyond Genera Palmarum : progress and prospects in palm systematics . Botanical Journal of the Linnean Society, 2016, doi : 10.1111 / boj.12401
- ↑ Rafaël Govaerts (ed.): Wallaceodoxa. In: World Checklist of Selected Plant Families (WCSP) - The Board of Trustees of the Royal Botanic Gardens, Kew . Retrieved June 5, 2016.
- ↑ Elodie Alapetite, William J. Baker, Sophie Nadot: Evolution of stamen number in Ptychospermatinae (Arecaceae): Insights from a new molecular phylogeny of the subtribe . Molecular Phylogenetics and Evolution, Volume 76, 2014, pp. 227-240, doi: 10.1016 / j.ympev.2014.02.026
- ^ A b c Charlie D. Heatubun, Scott Zona, William J. Baker: Three new genera of arecoid palm (Arecaceae) from eastern Malesia . Kew Bulletin 2014, Volume 69, 9525, doi: 10.1007 / S12225-014-9525-X
- ↑ Charlie D. Heatubun, Scott Zona, William J. Baker: Three New Palm genera from Indonesia . Palms, Volume 58, 2014, pp. 197-202.