A. arenosa, from the south of Europe, is a pretty annual in the spring garden or naturalised on old ruins or dry bare banks.
A. Calamus is now naturalised in most parts of Europe.
All the Thalictrums do well naturalised, and are readily increased from seed or careful division in early spring.
America, but is naturalised in some parts of Ireland.
C. Wolley Dod found N. maximus growing between Dax and Bayonne, probably naturalised.
Easily naturalised in any rough place, but not worth a place in the garden proper, being coarse and taking up much space.
It has lived on grass in peat, and, no doubt, could be naturalised easily enough on sandy peat soils which are wet in winter and spring and dry in summer and autumn.
It is already naturalised in parts of Britain, and is just the plant for a wild garden, in light and well drained soils.
It is easily grown and showy, and could be naturalised, especially on sandy and free soils.
It is hardy, and though not so robust in habit as H. fulva, it increases rapidly, and where the soil is good, might be naturalised.
It is naturalised in several parts of England, but its home is in the warmer parts of Europe.
It is not showy enough for every garden, but where admired it may be naturalised in light soil.
It is not showy, but interesting for the bog garden, or may be naturalised in damp peaty soil.
It is often naturalised on walls, ruins, and on rocky or stony banks.
Milk Thistle (Silybum) - S. marianum is a vigorous naturalised plant, 5 feet or more in height.
N. biflorus is naturalised in England and Ireland, but is a native of Europe.
Red Valerian (Centranthus Ruber) - A handsome, hardy border plant from the Mediteranean, and an old inhabitant of gardens, often also naturalised.
Suited for chalky banks or the rock garden, and some are suited for borders, while others may be naturalised in the grass in warm soil.
The common Borage is very pretty, naturalised in dry places or banks, where it might often be welcome for use as well as beauty.
Whenever an amateurs stock of bulbs is divided, it is wise to replant some in fresh ground, and any surplus may be naturalised in grass.
Where bold spring flowers are naturalised, a group of Giant Fennels will be effective, with their fine plumes in early spring.
Wild in the southern and eastern counties, and naturalised in other districts.