Variation in Molinia caerulea (L.) Moench, the Purple Moor Grass, in Relation to Edaphic Environments

Two diverse population of Molinia caerulea (L.) Moench, onegrowing on a Ca²⁺-rich, alkaline, Leblanc waste tip, the otheron an acid moorland, were investigated. It was anticipated thata comparative study of the morphology, growth and floweringpatterns, protein composition, specific isoenzyme and root-surfacephosphatase activities of both populations would clarify thetaxonomic status of populations of Molinia and help towardsunderstanding the ability of M. caerulea to colonize widelydiffering habitats. Both populations were identified as Moliniacaerulea caerulea. The Molinia growing on Leblanc spoil displayedcharacteristics typified by r-selected plants, i.e. displayinglarger flowers after faster development. Acid moorland plantsshowed greater vegetative development and were more typicalof K-selected types. These differences between the more vigorousshoot growth of the moorland compared to the waste tip plantspersisted under controlled conditions, irrespective of the mediain which they were grown. Root surface phosphatase activityshowed a plastic response to edaphic pH which may contributeto the success of M. caerulea caerulea in colonizing diversehabitats.Copyright 1995, 1999 Academic Press Molinia, edaphic extremes, variation, morphometry, enzyme activities, plasticity, colonization, taxonomy