Amomum riwatchii
| Amomum riwatchii | ||||||||||||
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| Amomum riwatchii | ||||||||||||
| M.Sabu & Hareesh |
Amomum riwatchii is a species of the genus Amomum withinthe ginger family (Zingiberaceae). This endemic occurs only in northeastern India.
description
Vegetative characteristics
Amomum riwatchii grows as a perennial , herbaceous plant that can reach heights of 1.5 to 2.2 meters. The rhizomes do not form runners, are 6 to 7 centimeters long and 3.5 to 4 centimeters thick, are creamy white on the inside and covered with scales on the outside. From each rhizome, several shoot axes, arranged in a cluster-like manner, emerge . At the base, the stems have green to dark reddish green, rarely also pale brown speckled, fluffy hairy leaf sheaths with bare, membrane-like edges, which are 2 to 2.5 centimeters wide and have a pointed upper end. The thick ligule are hairy on the outside and are 0.5 to 0.6 inches long; their edges are ciliate and their upper end is rounded to pointed.
Each stem has four to six leaves. The leaves are divided into a petiole and a leaf blade. The pale green leaf stalk is 1.5 to 7.5 inches long and hairy downy. The simple leaf blade is elongated-lanceolate with a length of 35 to 47 centimeters and a width of 5.5 to 9.5 centimeters with a pointed to wedge-shaped leaf base and a pointed, up to 3.5 centimeters long upper end. The green upper side of the leaf is covered with downy hairs like the pale green underside of the leaf. The leaf blades have a flat leaf vein on the upper side. The leaf margins are wavy and the green central rib is hairy downy.
Generative characteristics
The flowering period of Amomum riwatchii begins in May while the fruit ripens from August to September. Underground at the base of the stalk, directly from the rhizome, an inflorescence develops on a 1.5 to 2.5 centimeter long inflorescence stem , which is 9 to 15 centimeters long in total and in which the numerous flowers stand together. The outer, dark red, hairless and thick fleshy bracts are ovate to circular with a length of about 6 to 6.5 centimeters and a width of 5 to 5.5 centimeters with a pointed or blunt upper end and thin-skinned edges. The inner red bracts are 1.7 to 3.5 centimeters long and 0.7 to 1.3 centimeters wide and are ovate to ovate-lanceolate to linear-lanceolate and have a pointed to horn-like upper end and thin-skinned edges. Pre-leaves are missing. The flower stalk is about 0.8 inches long.
The hermaphroditic, white flowers are zygomorphic with a length of 7 to 7.5 centimeters and triple with double perianth . The three outer fluffy hairy, membrane-like, thick and pale red sepals are tubular fused together and are 4.3 to 4.5 centimeters in length and 0.5 to 0.6 centimeters in width longer than the corolla tube. They are unevenly lobed 0.8 to 1.5 centimeters deep and have a sharply pointed to horned, 0.7 to 1.4 millimeter long upper end. The white petals are fused to form a corolla tube 1.8 to 2 centimeters long and about 0.7 centimeters wide, with downy hair on the outside. The three white corolla lobes are bare. The middle corolla lobe is elongated-lanceolate with a length of 3 to 3.4 centimeters and a width of 1.2 to 1.4 centimeters with a hood-like folded and more or less sharply pointed upper end and thin-skinned edges. With a length of 3.5 to 3.7 centimeters and a width of 0.8 to 0.1 centimeters, the two lateral corolla lobes are somewhat narrower, lanceolate in shape, have a thin-skinned edge and a hood-like folded upper end. Only the middle of the three stamens in the inner circle is fertile . The fertile stamen is 2.2 to 2.4 inches long and its stamen is 0.8 to 0.9 inches long, about 0.3 inches wide, glabrous and white. The two cream-white halves of the anthers bag are elongated with a length of 1 to 1.2 centimeters. The staminodes of the inner circle are fused into an elongated, white and red-banded, bald labellum , which is 2.5 to 2.8 inches long and 1.4 to 1.6 inches wide. The white and hairless lateral staminodes are linear with a length of 0.5 to 0.7 centimeters. Three carpels are a dreikammerigen long, with a length of 0.5 to 0.6 centimeters and a diameter of about 0.6 centimeters elongated ovary adherent, which is externally hairy fluffy. Each ovary chamber contains numerous ovules . The stylus , about 5 centimeters long, is bare. The white scar is cup-shaped with a diameter of about 1 millimeter.
Each approximately 10 centimeter long fruit cluster, which stands on a 4 to 6 centimeter long stem, can contain six to nine fleshy capsule fruits . The fruit stalk is about 1 centimeter long. With a length of 2.2 to 2.4 centimeters and a diameter of 2.5 to 2.8 centimeters, the spherical capsule fruits are pale pink in color when ripe. They have a bare surface with three shallow furrows. The fruits contain many seeds. The black seeds have a white aril .
Occurrence
The natural range of Amomum riwatchii is in the state of Arunachal Pradesh in northeast India . As far as is known so far, it includes the area around the town of Mayodia in the Lower Dibang Valley district . It thrives there on the edges of evergreen forests at altitudes of 2100 to 2560 meters. The associated plant species include Arisaema concinnum , Gaultheria fragrantissima , Impatiens arguta , Maianthemum oleraceum and Musa puspanjaliae, as well as various types of bamboo and strawberries ( Fragaria spec.).
Taxonomy
The first description as Amomum riwatchii was made in 2018 by Mamiyil Sabu and Vadakkoot Sankaran Hareesh in Botany Letters , Vol 165. The epithet riwatchii refers to the the Indian state of Arunachal Pradesh -based Research Institute of the World's Ancient Traditions Cultures and Heritage (RiWatch), a non-governmental organization , the who is committed to maintaining biodiversity.
swell
- Vadakkoot Sankaran Hareesh & Mamiyil Sabu: Amomum riwatchii (Zingiberaceae): a new species from northeastern India . In: Botany Letters . tape 165 . Taylor & Francis Group, 2018, ISSN 2381-8107 , doi : 10.1080 / 23818107.2018.1437073 .