Interpopulation studies of Stachys x ambigua Sm. in Orkney, Shetland and Northern Scotland and a taxonomic account of the genus Stachys in Iraq
An exhaustive survey of chromosome numbers presently known in the genus Stachys is reviewed. Their potential usefulness for an infrageneric classification is discussed. Variation in local populations of Stachys. Morphological analysis of a wide range of plants of S. x ambigua from Orkney, Shetland, and the mainland of northern Scotland was undertaken from material grown experimentally at Aberdeen. The analysis revealed 2 biotypes of S. x ambigua in the Northern Isles. a) A widespread biotype present throughout 14 islands of Orkney, the mainland of Orkney and Bettyhill. b) A locally raised restricted biotype at the Bay of Carness on mainland Orkney. A locally raised biotype (c) was found at Loch Meiklie, on mainland Scotland. Shetland S. x ambigua is very close to the widespread biotype and cannot be distinguished from it morphologically. These plants may belong to the same biotype (a). Specimens from the collections made by Borrer and Hooker from Glen Elg and Loch Carron and described in English Botany (1810) overlap in morphology and differ from the 3 biotypes described above. The material used for the original drawing came from Orkney but has not been located, and is presumed to be destroyed. Studies on Stachys of Iraq: Studies of herbarium specimens showed that 20 species of Stachys occur in the mountainous Kurdistan area and Jabal Sinjar of Iraq. One species is new. Two species S. iraqensis Bhattacharjee and S. nephrophylla Rech. f. are reduced to subspecies and varietal rank respectively.