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''Halothamnus'' is a genus of the subfamily Salsoloideae in the family Amaranthaceae (s.l., now including Chenopodiaceae). The scientific name means saltbush, from the Greek ἅλς (''hals'') "salt" and θαμνος (''thamnos'') "bush". This refers either to salty habitats or to the accumulation of salt in the plants. The genus is distributed from Southwest and Central Asia to the Arabian peninsula and East Africa. == Description == Most species of ''Halothamnus'' are small shrubs or sub-shrubs, two species are annuals. The alternate leaves are sitting without basal narrowing at the branches. They are simple, entire, half-terete or flat and slightly fleshy (succulent). The bisexual inconspicuous flowers are sitting solitary in the axil of a green bract and two green bracteoles. The five free tepals are green with membranous margins above a transverse line and colourless below. Five stamens arise from a cup-like structure (hypogynous disc) at the base of the flower. One ovary is formed by two carpels, with a thick pistil, and two stigmas. The one-seeded, horizontally flattened fruit keeps being enclosed by the hardening perianth. Wings develop from the transverse zone at the outer side of the tepals. Below the wings, the peranth forms a thick and lignified tube with a widened base. Its bottom side has five pits arranged in a ring, surrounded by a rim. These fruit characteristics are essential for the genus ''Halothamnus''. file:Halothamnus_lancifolius_fruit.JPG|Fruit (lateral view) of ''Halothamnus lancifolius'' file:Halothamnus_iranicus_fruit.JPG|Fruit (bottom) of ''Halothamnus iranicus'' The pollen grains are nearly ball-shaped, 18-38 µm in diameter, with 12-29 pores scattered all over the surface (pantoporate), just like it is typically for the goosefoot-family. The species differ from each other in pollen diameter and number of pores, the southern species with the smallest and the northern species with the largest pollen grains.〔Gabriele Kothe-Heinrich: ''Revision der Gattung ''Halothamnus'' (Chenopodiaceae)''. Bibliotheca Botanica Bd. 143, Schweizerbart, Stuttgart 1993, ISBN 978-3-510-48014-2, p.13-14 and p.174-176. 〕 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Halothamnus」の詳細全文を読む スポンサード リンク
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