BIOLOGICAL FLORA OF THE BRITISH ISLES

Subgenus Euerica, section Loxomeria. A dwarf evergreen shrub, usually 0.2-0.4m tall but up to 0.8m in dense vegetation and to 2.0 m in afforested areas (Underhill 1990). When growing as an isolated plant, it forms a less dense bush than Erica tetralix but in its typical association with Molinia caerulea, Calluna vulgaris and E. tetralix its stems become ascending or decumbent. Adventitious roots are produced where the bases of the stems come into contact with a moss or litter layer. The leaves are in whorls of three (occasionally four where hybridization occurs with E. tetralix), 2-4 mm long and ovate to oblong-lanceolate with glandulartipped cilia on the apparent margins and a glabrous abaxial midrib. The branches are pubescent, short and numerous, tending to be whorled beneath the current inflorescence. The inflorescence is of 15-45 flowers in a unilateral raceme, 50-120mm long. The pedicels are 1-2mm long, the calyx-lobes are oblong-lanceolate, ciliate and pubescent and corolla 8-12 mm, urceolate, mouth oblique, deep reddish-pink although occasional white-flowered forms occur (McClintock 1967; Nelson & McClintock 1983). There are eight stamens with anthers included; the anther surfaces are papillate but lack appendages. The capsule is obconical and glabrous, 4 mm wide and 3 mm long. The mature seed is 0.3-0.5mm in length and has an average air-dried weight of 20 ,ug (12-32 ,ug). No varieties have been described although a number of reasonably distinct cultivars have been named; there are 17 listed by Denbeigh Heather Nurseries (D. Small, personal communication). Variation in the hybrid between E. tetralix and E. ciliaris, E. x watsonii Benth., is naturally greater and 11 cultivars are listed (D. Small, personal communication). Erica ciliaris is a plant with a Lusitanian distribution found in heath and mire communities from the north-west tip of Africa northwards through west-