Morphology and position of the shoot apex in some temperate grasses

Abstract

SUMMARYThe morphology and position of the shoot apex in field swards was studied in 12 grasses for 12 months, in eight related grasses in 2 years, and in seedlings, young tillers and older tillers of Lolium perenne.Lolium multiflorum had relatively large numbers of primordia, long apices, which were above ground or near ground level, and a small length of apex per primordium. Festuca arundinacea had few primordia, a large length of apex per primordium, and apices which were well below ground or near ground level. Lolium perenne, Festuca pratensis and Lolium × Festuca hybrids were intermediate between Lolium multiflorum and Festuca arundinacea in numbers of primordia and length of apex per primordium. Festuca rubra and Dactylis glomerata had rather small numbers of primordia, whereas Phleum pratense had relatively large numbers of primordia and of unemerged and emerged leaves.The numbers of leaf primordia in Lolium perenne increased as the seedling main shoots or the tillers grew older, while the numbers of unemerged leaves per shoot remained more constant.The morphology, position and protection of shoot apices are discussed in relation to differences between species in rate of establishment and persistence.