A calcifuge is a plant that does not tolerate alkaline (basic) soil. The word is derived from the Latin 'to flee from chalk'. These plants are also described as ericaceous, as the prototypical calcifuge is the genus Erica (heaths). It is not the presence of carbonate or hydroxide ions per se that these plants cannot tolerate, but the fact that under alkaline conditions, iron becomes less soluble. Consequently, calcifuges grown on alkaline soils often develop the symptoms of iron deficiency, i.e. interveinal chlorosis of new growth. There are many horticultural plants which are calcifuges, most of which require an 'ericaceous' compost with a low pH, composed principally of Sphagnum moss peat. Alternatively sulphur chips may be used to lower soil pH. A plant that thrives in lime-rich soils is known as a calcicole.
Examples
Order Ericales
Ericaceae Andromeda polifolia Calluna (common heather) Cassiope lycopodioides Daboecia Enkianthus campanulatus Erica (but not E. carnea or E. erigena) Gaultheria mucronata Kalmia latifolia (calico bush) Pieris Rhododendron (many species of rhododendron and azalea) Vaccinium corymbosum (northern highbush blueberry) Vaccinium myrtillus (bilberry)
Sarraceniaceae (carnivorous) Pitcher plants of the genera Sarracenia, Darlingtonia, and Heliamphora
Styracaceae Styrax wilsonii
Theaceae Camellia sinensis (Tea plant)
Order Caryophyllales
Droseraceae (carnivorous) Drosera (sundew species; but some species are calcitolerant or calciphilous) Dionaea muscipula (Venus flytrap)
Nepenthaceae (carnivorous) Nepenthes (pitcher plants; but some species are calcitolerant or even calciphilous)
Order Lamiales
Lentibulariaceae (carnivorous) Utricularia sect. Calpidisca and some other subgenera (non-epiphytic terrestrial bladderworts; there are some species that prefer neutral pH or are calciphilous)
Other orders
Asteraceae Arnica montana
Columelliaceae Desfontainia spinosa
Cornaceae Cornus florida (dogwood)
Elaeocarpaceae Crinodendron hookerianum
Fagaceae Quercus (Some species of oak)
Gentianaceae Gentiana acaulis Gentiana sino-ornata
Hamamelidaceae Corylopsis pauciflora Disanthus cercidifolius Fothergilla major Hamamelis vernalis (spring witch hazel)
Papaveraceae Meconopsis grandis (Himalayan blue poppy)
Poaceae Avena sativa (oat)
Proteaceae Embothrium coccineum Grevillea rosmarinifolia
Schisandraceae Illicium anisatum
References
External links Tyler, G. 1996. Mineral nutrient limitations of calcifuge plants in phosphate sufficient limestone soil. Annals of Botany. 77 (6) 649-656.