There are only three, Glenkinchie, Auchentoshan and Ladyburn. Ladyburn is not bottled as a single by its owners.
The region embraces the mainland of Scotland south of the Central Belt (a line drawn between the Forth and Loch Lomond). There was a time, in the 1850s, when every town of any size in the Lowlands had its distillery, to supply the English market as well as local demands. For the style of Lowland whisky is much lighter than Highland, with little or no peating, and this had much broader appeal. By the 1880s almost the entire production of the Lowland distilleries went for blending: today, it is possible (and more cost effective) to create Highland malts with a light character to suit the requirements of blenders.
Auchentoshan Distillery is on the northern edge of Glasgow and was founded in 1800. It has a light, cereal nose with a lemony tinge and a clean, dry finish. Glenkinchie Distillery is situated at Pencaitland, just outside Edinburgh. Its product is an excellent representative of the style of Lowland malt whiskies: fragrant yet reserved, with a clean, fresh flavour and a dry, gingery finish.
Rosebank was generally considered to be the best Lowland malt.
It seems to be a characteristic of Lowlands that they can take very long maturation without becoming woody: St.Magdalene 1965 is wonderful (although the distillery in Linlithgow was turned into flats in 1983).
Lowland Malts' Characteristics
Lowlands typically have a dry finish, which makes them excellent aperitifs. The dryness comes from the malt itself, not from peat (Lowlands tend to use unpeated malt), and this also lends a certain sweet fruitiness to the flavour and mouthfeel. Their aromatic intensity is low, and tends to be grassy or herbal, with grainy and floral notes. It used to be said that they leant a brandy-like flavour to a blended whisky.