A bulbous perennial herb which is naturalised on the sea shore at Porth Dinllaen (Caerns.) and in a saltmarsh beside the river Lune (W. Lancs.). Elsewhere, it occurs as a relic of cultivation or a food-refuse alien on rubbish tips and waste ground. It is diploid but most cultivars are totally sterile. Lowland.
A bulbous perennial herb found as a native in a range of habitats, usually on thin soils over limestone, serpentine and basic igneous rocks; it sometimes grows in rank grass on deeper soils, and in crevices of riverside bedrock. As an alien it grows on roadsides and rubbish tips. Lowland.
A bulbous, perennial herb spreading mainly by bulbils in rough grassland and waste ground, on road verges and track sides and by railways. It sometimes occurs in more natural habitats such as sandy river banks, open woodlands on well-drained soils and a variety of coastal situations. Lowland.
A bulbous perennial herb found as a possible native at only two localities: on dry, rocky S.- and W.-facing slopes in the Avon Gorge (W. Gloucs.), and on rough, sandy ground by the sea at St. Aubin`s Bay, Jersey. Both populations are very small. Lowland.
A bulbous perennial herb, spreading by ant-dispersed seed on roadsides, in hedge banks, on field margins and in rough and waste ground. Lowland.
A bulbous perennial herb of moist woodlands, sometimes growing in more open situations such as riversides and hedge banks and occasionally in rock crevices, in scree and on coastal cliff ledges. Regeneration is primarily by seed. Generally lowland, but reaching c. 450 m at Great Clowder, Malham (Mid-W. Yorks.).
A bulbous perennial herb of dry, neutral or calcareous soils, generally occurring in summer-dry grasslands, hedgerows, roadsides and cultivated ground, and formerly a serious weed of cereal crops in S.E. England. Also found on coastal cliff ledges in W. Scotland. Generally lowland, but reaching 455 m in Wensleydale (N.W. Yorks.).
A deciduous tree found on roadsides, in town parks and in amenity areas. Unlike other Alnus species, it thrives on poor, dry soils, even those over chalk. Street trees flower and fruit freely; the seed is wind dispersed and seedlings are frequent by pavements and on waste ground. Generally lowland, but reaching 305 m at Shap (Westmorland).
A deciduous tree of damp or wet, basic to moderately acidic soils, found beside rivers, streams, canals, lakes and ditches, and in flood plains, fens and bogs, carr and wooded dune-slacks. It can rapidly seed into open sites, producing even-aged stands of mature trees, but seedlings are very shade- and drought-sensitive, so regeneration in woodland is often poor. It is also widely planted. 0-470 m (Garrigill, Cumberland).
A deciduous tree, widely planted in parks, on roadsides, reclaimed tips and river banks, and sometimes in small plantations. It is very hardy and tolerant of poor, wet soils, making it useful in amenity planting in the north. It sometimes spreads to, and becomes naturalised on, waste ground and railway embankments. It reproduces by seed and suckering. Lowland.