Arthrocnemum Moq.

20. Arthrocnemum Moq. 1

Articulate, glabrous, dwarf shrubs. Leaves opposite, scale-like, the bases of each pair amplexicaul, fused to form a segment. Inflorescence spicate, segmented; each fertile segment composed of two 3-flowered cymes immersed in the pair of bracts arising from the node above; the flowers of each cyme more or less equal in size, the central distinctly separating the laterals. Perianthsegments usually 4; stamens 2.

The delimitation of this genus from Salicornia is that proposed by C. E. Moss, Jour. S. African Bot. 20: 1 -22 (1954), but there is much disagreement as to the limits of these genera. All species occur mainly in salt-marshes.

1 Flowers of each cyme falling to leave an undivided hollow in the segment; seeds black; testa hard, tuberculate 3. glaucum

1 Flowers of each cyme falling to leave a tripartite hollow in the segment; seeds greenish-browntogreyish; testathin, membranous, covered with short conical or curved hairs

2 Usuallywithcreeping,subterraneanstems;green,oftenbe­ coming red or brown; seeds covered with curved orhooked hairs 1. perenne

2 Always without creeping subterranean stems; usually glaucous; seeds covered with ± conical hairs 2. fruticosum 12