A monocarpic herb, rarely native more than 100 m from the coast. It usually grows in shallow, nutrient-enriched soils, occurring most frequently amongst vegetation in sea-bird roosts, and on ground enriched by garden waste. Plants are killed by severe frost and the species is therefore restricted to mild micro-climates near the sea. Lowland.
It is difficult to define the native range of L. arborea, as it is taken from the wild into gardens in some areas and escapes from gardens in others. Although there are local losses, these are more than offset by the spread of plants from coastal gardens into nearby ruderal habitats.
Light (Ellenberg): 9
Moisture (Ellenberg): 6
Reaction (Ellenberg): 7
Nitrogen (Ellenberg): 8
Salt Tolerance (Ellenberg): 3
January Mean Temperature (Celsius): 5.4
July Mean Temperature (Celsius): 15.5
Annual Precipitation (mm): 1023
Count of 10km squares in Great Britain: 188
Count of 10km squares in Ireland: 72
Count of 10km squares in the Channel Isles: 13
Atlas Change Index: 1.2
Scarce Atlas Account
Lavatera arborea L.
L. arborea is a strictly maritime species, very rarely found more than 100 metres from the coast. It usually grows on shallow soils (10-30 cm) which have developed over a range of rocks from granite to limestone. It occurs in two main habitats. The first is amongst the vegetation of sea bird roosts where the chief associates are Armeria maritima, Atriplex species, Beta vulgaris subsp. maritima, Festuca rubra, Plantago coronopus and Silene uniflora. The second consists of areas that have had nutrient enrichment, most usually from garden rubbish. Here the most commonly associated species are Beta vulgaris subsp. maritima, Dactylis glomerata, Festuca rubra and Rumex crispus. The soils where L. arborea grows are always nutrient enriched from guano or decomposing rubbish.
L. arborea is biennial or a very short-lived perennial and is generally monocarpic. Reproduction is exclusively by seed which is shed in late summer to early autumn. Germination is sporadic in autumn and commoner in the spring. Mature plants, and particularly the seedlings, are extremely frost sensitive, with a temperature of -5 °C for three hours killing all plants. No seedlings survived the winter in exposed situations in the Port Logan Botanical Garden (on the Galloway coast) though 40% survived in very sheltered situations. Mature plants are rather more tolerant and can survive very light frost of short duration. Establishment normally requires disturbed, open and moist conditions with a relatively low soil salinity level but more mature plants are very resistant to wind-borne salt spray. The quantity of fruit produced appears to be directly related to the size of the plant. Setting of fruit is usually good. Fruit dispersal is limited, with most of the rather heavy mericarps falling in the immediate vicinity of the parent.
L. arborea may be decreasing in some areas as a result of less intensive disturbance of sea-cliff vegetation and progressive restriction of sea-bird roosts to the more inaccessible offshore rocks. However, this is more than offset by the spread of the plant from coastal gardens onto disturbed and nutrient-enriched ground.
L. arborea is a species of Mediterranean-Atlantic distribution, reaching its northern limit of 55 °N in Britain.
Records from inland and east coast sites, reported as L. arborea, are more likely to be another Lavatera species. It has been confused with L. olbia in gardens.
A. J. C. Malloch
PLANTATT - Attributes of British and Irish plants. (.zip 1455KB) This dataset was compiled and published in 2004, and last updated in November 2008. Download includes an Excel spreadsheet of the attributes, and a PDF explaining the background and nomenclature. Note that the PDF version is the booklet as published, whereas the Excel spreadsheet incorporates subsequent corrections. A hardcopy can be purchased from the Centre for Ecology and Hydrology.
Atlas text references
1990. Flora dels Països Catalans, II. Crucíferes-Amarantàcies.
1994. Scarce plants in Britain.
1979. An experimental investigation into the ecology of some maritime cliff species I. Field observations. Journal of Ecology. 67:283-292.