Halimione


Halimione is a plant genus from the subfamily Chenopodioideae of the family Amaranthaceae. It is a sister genus of Atriplex and has sometimes been included in this genus.

Description

The species in genus Halimione are annual or perennial herbs with silvery grey stems and leaves.
Their stems grow prostrate, ascending or erect. The leaves are opposite in lower part and alternate in upper part of the plants. The leaf blade is oblong with entire margins.
Plants are monoecious. The spicate inflorescences consist of inconspicuous flowers. Male flowers comprise 4-5 perianth segments and 4-5 stamens. Female flowers have 2 totally concrescent, three-lobed bracteoles which enclose the ovary, a perianth is missing.
The pericarp is tightly adherent to the inner side of the bracteoles, and also tightly adherent to the seed. The seed is vertically orientated, with a thin, membraneous seed coat. It is anatomically different from Atriplex.
Halimione pedunculata and Halimione verrucifera have a chromosome number of 2n = 18, Halimione portulacoides 2n = 36.

Distribution

Halimione is distributed in Europe, North Africa, and Asia, ranging from Southwest Asia, and Central Asia to China.

Systematics

The genus has been first described in 1822 as Halimus by Karl Friedrich Wallroth. But this name was illegitimate, as there existed already Halimus Patrick Browne in family Portulacaceae. replaced this illegitimate name by the valid name Halimione in 1938. Type species is Halimione pedunculata Aellen.
During the following years, Halimione has sometimes been included in Atriplex. But phylogenetic research by Kadereit et al. revealed, that Halimione is a distinct sister genus of Atriplex.
Halimione comprises 3 species in 2 sections: