A rhizomatous perennial herb which grows in Britain in two habitats: on dry woodland slopes over chalk in the Chilterns, and in damp woodlands over clay in the Weald. Elsewhere it is an escape from cultivation by roads and in woodland and parkland. Lowland.
The distribution of C. bulbifera in its major strongholds is stable. It is not known whether the disjunct, apparently native populations reflect a wider earlier range, ancient long-distance dispersal or more recent colonisation. C. bulbifera sometimes escapes from cultivation, but these plants differ in leaf-shape.
European Temperate element, with a continental distribution in W. Europe.
Light (Ellenberg): 3
Moisture (Ellenberg): 5
Reaction (Ellenberg): 7
Nitrogen (Ellenberg): 6
Salt Tolerance (Ellenberg): 0
January Mean Temperature (Celsius): 3.7
July Mean Temperature (Celsius): 16.4
Annual Precipitation (mm): 780
Height (cm): 70
Perennation - primary
Life Form - primary
Clonality - primary
Clonality - secondary
Count of 10km squares in Great Britain: 25
Count of 10km squares in Ireland: 0
Count of 10km squares in the Channel Isles: 0
Atlas Change Index: 0.36
Scarce Atlas Account
Cardamine bulbifera (L.) Crantz
This is a plant with two contrasting habitats. In the Chilterns it is found in beech woodland on relatively dry slopes with underlying chalk, generally close to tracks and paths. It grows as patches 1-2 metres in diameter, in areas which are free of most other vegetation; or more thinly scattered and then associated with Rubus fruticosus, Mercurialis perennis and the typical ground flora of such woodland. In the Kent and Sussex Weald it grows in damp woodlands on Wealden clay, often closely associated with streams and damp places, frequently on the steep banks of a stream, in smaller patches and deeper into the woodland than in the Chilterns; often with Carpinus betulus as the tree cover and Cardamine flexuosa, Carex pendula and Hyacinthoides non-scripta in the ground flora. It flourishes in both types of habitat for a few years when the tree canopy is opened up but forms much more stable colonies where there is little interference and the light intensity is relatively low. It is confined to the lowlands.
C. bulbifera is perennial with a cream-coloured, coral-like rhizome. Many mature plants flower (though only for a short period) and bear axillary bulbils. The remainder produce bulbils but no flowers. Reproduction is normally by means of these bulbils but a few plants in some colonies sometimes produce viable seed, remaining green and leafy long after the others have withered away and the bulbils fallen. There are generally many times more juvenile plants in a colony than mature plants. It flowers from seed or bulbil after 3-4 years.
Although C. bulbifera has been well-recorded in the past, it is still possible to discover new sites but there is no evidence to suggest that there are hitherto unrecorded populations. It has disappeared from only a few localities, these being where a wood has been clear-felled or replanted with conifers. On the whole the distribution appears stable.
In Europe this species occurs from southern Scandinavia and France to the Black Sea, often in the mountains. It does not extend to the Mediterranean area. It is also found in south-west Asia, reaching its eastern limit in the Caucasus.
C. bulbifera has been introduced in a number of places in Britain and in many it still persists. In the West Country, the form ptarmicifolia, a bigger plant with larger leaves and browner bulbils than the native one, is a common introduction.
For a detailed account of this species, see Showler & Rich (1993).
A. J. Showler
Atlas text references
1986. Atlas of north European vascular plants north of the Tropic of Cancer. 3 vols.
Jalas & Suominen (1994)
1965. Vergleichende Chorologie der zentraleuropäischen Flora. Volume 1. 2 vols.
1991. Crucifers of Great Britain and Ireland. Botanical Society of the British Isles Handbook no. 6.
1993. Cardamine bulbifera (L.) Crantz (Cruciferae) in the British Isles. Watsonia. 19:231-245.
1994. Scarce plants in Britain.