Amomum calcaratum
| Amomum calcaratum | ||||||||||||
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| Systematics | ||||||||||||
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| Scientific name | ||||||||||||
| Amomum calcaratum | ||||||||||||
| Lamxay & MF Newman |
Amomum calcaratum is a species of the genus Amomum withinthe ginger family (Zingiberaceae). This endemic occurs only in central Laos .
description
Vegetative characteristics
Amomum calcaratum grows as a perennial , herbaceous plant that can reach heights of up to 1.8 meters. The red to reddish-brown rhizomes are about 0.5 to 0.8 centimeters thick, grooved and bare on the outside and covered with scales. The leathery, tomentose-haired and grooved pink to dark red-brown scales are egg-shaped with a length of 1 to 2 centimeters with a pointed upper end and ciliate edges. The rhizome is about 7 centimeters long between the individual “pseudostems”. From each rhizome about ten clump-forming shoot axes or “pseudostems” go off. On the slightly swollen base with a diameter of 0.5 to 1.5 centimeters, the stems have reddish green to green, tomentose hairy on the outside and furrowed to smooth leaf sheaths with ciliate edges. The red to light green, leathery and egg-shaped ligules are tomentose on the outside and are 0.1 to 0.5 centimeters long; their upper end is edged and their edges are ciliated.
Each stem has 5 to 22 leaves. The leaves are divided into a petiole and a leaf blade. The green runny petiole is relatively short with a length of 0.1 to 0.2 centimeters and, with the exception of the hairy base, glabrous. With a length of 13 to 25 centimeters and a width of 2 to 7 centimeters, the simple leaf blade is oblong to elliptical to obscure-lanceolate with a pointed leaf base and a long tailed upper end. The glossy green top of the leaf is bare just like the glossy green underside of the leaf. The leaf blades show a conspicuous leaf veins on the underside. The leaf margins are entire.
Generative characteristics
Subterranean and close to or directly at the stem base from the rhizome develops on an approximately 10 centimeter long and 0.4 to 0.8 centimeter thick, shiny red and bare inflorescence stem with a length of about 5 centimeters and a diameter of about 3 Centimeter ellipsoidal inflorescence in which the approximately four flowers are close together. One or two inflorescences are formed per stem. The inflorescence shaft is covered with red to dark red-brown, hard leathery, furrowed and shaggy hairy scales on the outside, which are tubular at the base of the shaft with a length of 1 to 2.5 centimeters and a width of about 0.8 centimeters. The scales in the upper shaft area are egg-shaped with a length of 2 to 5 centimeters and a width of 1.8 to 2 centimeters wide with a pointed and short spurred upper end and edges with relatively long white trichomes . The red to dark red-brown, outside tomentose hairy and hard leathery and on the top paper-like, furrowed bracts are with a length of 2.3 to 3 centimeters and a width of 0.5 to 0.7 centimeters boat-shaped to lanceolate with pointed and about 0.5 cm long spurred upper end and ciliate edges. When the fruit ripens, the wrapper leaves are about 4.5 to 5 centimeters long and about 2 centimeters wide and fall off after a short time. The light brown, membrane-like but very thin bracts are fused to form a 1.2 to 1.3 centimeter long and 0.4 centimeter wide tube with tomentose hair at the base, which is serrated twice. The two teeth are 0.1 to 0.2 inches long.
The hermaphrodite flowers are zygomorphic and threefold with double, white perianth . The three brownish pink and membrane-like, but very thin sepals are fused together in a tubular shape and are about the same length as the corolla tube with a length of 1.5 to 1.6 centimeters and a width of about 0.3 centimeters. They are double-serrated, with the calyx teeth being 0.4 to 0.5 inches long and having a pointed upper end with a small thick spur. The three white and 3 to 3.2 centimeters long, leathery petals are fused into an approximately 1.5 centimeter long, shaggy-haired corolla tube on the outside, which is bare on the outside as well as on the inside. There are also three white crown lobes. The middle corolla lobe is about 1.5 centimeters long and about 1 centimeter wide with a cap-shaped upper end. The two lateral crown lobes are slightly narrower with a length of about 1.5 centimeters and a width of 0.7 to 0.8 centimeters and also have a cap-shaped upper end. Only the middle of the stamens of the inner circle is fertile . The fertile stamen has a flattened, about 0.2 centimeter long, bare, white stamen . The two white halves of the hairless anthers are oblong with a length of about 0.8 centimeters and a width of about 0.4 centimeters. The staminodes of the inner circle have grown together to form a labellum. The approximately 1.7 centimeters long and 1.6 to 1.8 centimeters wide labellum is white with a yellow center and red stripes and dots; it is tomentose at its base and has a wavy edge. The lateral, white staminodes are elongated with a length of about 0.3 centimeters. Three carpels are fused into a three-chambered, hairy, spherical ovary with a diameter of about 0.3 centimeters . Each ovary chamber contains only about five ovules . The stylus is hairy. The cup-shaped scar is bare with the exception of the ciliate tip.
The shaft of the infructescence is red, tomentose, about 6 to 10 inches long and 0.4 to 0.7 inches thick. In one with a length of 4 to 5 centimeters and a diameter of about 5 centimeters, there are three to five capsule fruits . The spherical capsule fruits with a diameter of about 1 centimeter turn pinkish red when ripe. Each of the three fruit compartments contains three to five seeds. The surface of the fruit flaps is hairy and soft but prickly. The bare seeds are spherical with a diameter of 3 to 4 millimeters.
Occurrence
The natural habitat of Amomum calcaratum located in the central Laos located Khammouane Province . As far as is known so far, it includes the area around Bane Khoun Ngeun in the Hinboon district . It thrives there at altitudes of 285 to 381 meters in evergreen forests over limestone .
Taxonomy
It was first described as Amomum calcaratum in 2012 by Vichith Lamxay and Mark Fleming Newman in the Edinburgh Journal of Botany , Volume 69, Number 1, Page 110.
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- Vichith Lamxay, MF Newman: A revision of Amomum (Zingiberaceae) in Camboida, Laos and Vietnam . In: Edinburgh Journal of Botany . tape 69 , no. 1 . Trustees of the Royal Botanic Garden Edinburgh, 2012, p. 99-206 , doi : 10.1017 / S0960428611000436 .