Synechanthus
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| H. Wendl. |
Synechanthus is an American genus of palm . Their representatives are moderately large palm trees in the undergrowth of forests. They are common ornamental plants.
features
Synechanthus is a moderately large, single-stemmed or clump-forming, unreinforced palm with pinnate leaves. They bloom several times, are monoecious , and sometimes bloom while they are still stemless. The trunk is slender, usually upright, rarely lying down, smooth and yellowish to shiny or dark olive green. The trunk is covered with clear, distant leaf scars.
The chromosome number is 2n = 32.
leaves
The leaves are pinnate reduplicate. The leaf sheath is long on young leaves, but tears open very early compared to the petiole. The remnants are only differentiated from the stem by a narrow, mostly fibrous, dry strip along the edge. The petiole is circular in cross section. The rachis is angular on the upper side and rounded on the lower side. The leaflets are broadly reduplicated at the point of attachment, with one or more main veins protruding from the top. Sometimes the leaf blade is undivided, then two-parted (bifid) at the tip.
Inflorescences
The inflorescences are between or under the leaves. They are single or double branched. They stand upright when they bloom; when they ripen, they are curved or pendulous. The peduncle is long. The cover sheet is short, tubular, encompassing the stem as a sheath and ultimately disintegrating into fibers. There are four to five bracts on the peduncle, which are similar to the previous leaf, but longer. They start at ever greater distances from one another. The last bract dominates the peduncle. The inflorescence axis is usually long. The flower-bearing axes (rachillae) are slender, about the same length, square to clearly flattened and flexible. Their tips are even slimmer and almost prickly.
blossoms
The flowers are usually arranged in distich coils . A coil consists of a proximal female flower and 5 to 13 distal, biseriate male flowers. At the wrap, the distal flower opens first, the further opening is basipetal.
The male flowers are green in the bud and golden-yellow in flowering. In the bud they are triangular when compressed. The three sepals have grown together to form a flat, pointed, three-lobed cup. The three petals are valvat . There are either six stamens with short filaments that are curved in the bud and upright to flower; or there are three stamens with long filaments that are clearly curved and protrude horizontally towards the flower. The anthers are baxifix, slightly bifid at the tip and base, and open to latrors. The rudiment of the stamp is small or missing entirely. The pollen is ellipsoidal and slightly asymmetrical. The germ opening is a distal sulcus. The longest axis measures 25 to 32 microns.
The female flowers are yellowish at flowering time. The three sepals are fused to form a three-lobed cup. The three petals are imbricat , twice as long or more than the sepals. The staminodes may be absent; or there are three small ones; or they are fused into a six-lobed ring that is partially connected to the crown. The gynoeceum is egg-shaped, three-way, each with an ovule , with three scars that are short and curved back. The ovules start laterally, are campylotropic and laterally flattened.
Fruits and seeds
The fruits are relatively large and round to oblong. They are yellow and turn red when ripe. You have basal scar remains. The exocarp is smooth, the mesocarp fleshy with a few anastomosing, flat fibers towards the membranous endocarp . The seed is not connected to the endocarp. The basal hilum is inconspicuous. The raphenous branches are large and rise adaxially from the base, anastomose little, bend laterally and descend again abaxially. The endosperm is homogeneous or slightly to clearly furrowed (ruminate).
Distribution and locations
The two types occur in southern Mexico, Central America and northwestern South America. They are quite common in moist forests at sea level and low altitudes, but also rise up to 1200 m above sea level.
Systematics
The genus Synechanthus H. Wendl. is placed within the family Arecaceae in the subfamily Arecoideae , tribe Chamaedoreeae . The genus is monophyletic . The relationship of Synechanthus within the tribe has not been clarified.
The Royal Botanic Gardens, Kew's World Checklist of Selected Plant Families recognizes the following species:
- Synechanthus dasystachys De Gracia & Grayum : The home of the species first described in 2016 is Panama.
- Synechanthus fibrosus (H. Wendl.) H. Wendl. : The home is Mexico, Belize, Guatemala, Honduras, Nicaragua, Costa Rica and Panama.
- Synechanthus warscewiczianus H. Wendl. : The homeland is Nicaragua, Costa Rica, Panama, Colombia and western Ecuador.
literature
- 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. 375-377.
Individual evidence
- ↑ a b c d Rafaël Govaerts (Ed.): Synechanthus. In: World Checklist of Selected Plant Families (WCSP) - The Board of Trustees of the Royal Botanic Gardens, Kew . Retrieved August 4, 2018.
