| Front matter | _ | 
            
              | Table of Contents | _ | 
            
              | Issue 1 | _ | 
            
              | Obituary: Patricia Geissler | _ | 
            
              | Article: Similarity is only skin-deep : the use of comparative plant anatomy as illustrated by a study of columnar cacti from Chile (Eulychnia and Echinopsis, Cactaceae) | 1 | 
            
              | Article: Switzerland and the invasive plant species issue | 11 | 
            
              | Article: Nunataks and peripheral refugia for alpine plants during quaternary glaciation in the middle part of the Alps | 25 | 
            
              | Article: Molecular approach to the identification and characterization of natural hybrids between Orchis pauciflora Ten. and Orchis quadripunctata Cyr. ex Ten. (Orchidaceae) | 31 | 
            
              | Article: Une espèce nouvelle de Pandanus sect. Martellidendron (Pandanaceae) de la péninsule de Masoala, Madagascar | 41 | 
            
              | Article: Allergenic pollen types in the atmosphere of Santiago de Compostela (NW Spain) :  a pollen calender for the last six years | 51 | 
            
              | Article: Morphological and molecular diversity of Swiss common bean cultivars (Phaseolus vulgaris L., Fabaceae) and their origin | 61 | 
            
              | Article: Fortschritte in der Floristik der Schweizer Flora (Gefässpflanzen) (mit Berücksichtigung der an die Schweiz angrenzenden Gebiete). 59. Folge (Berichtsjahr 1998-1999, 2. Teil) | 79 | 
            
              | Issue 2 | 101 | 
            
              | Article: The taxonomic position of the controversial taxon Orchis clandestina (Orchidaceae) : karymorphological and molecular analyses | 101 | 
            
              | Article: Distribution of diploid sexual triploid apomictic dandelions (Taraxacum sect. Ruderalia) along two altitudinal gradients in Switzerland | 109 | 
            
              | Article: Grimmia nutans Bruch en France méridionale et Grimmia elatior Bruch ex Bals. & de Not., respectivement nouveaux pour la bryoflore d'Europe occidentale et de Corse | 115 | 
            
              | Article: Phytosociology and ecology of the Festuca puccinellii-grasslands in the Northern Apennines (N-Italy) | 125 | 
            
              | Article: Populationsgeschichte des seltenen Kammfarns (Dryopteris cristata) in der Schweiz | 151 | 
            
              | Article: Analysis of the adventive flora of a Greek city : the example of Patras | 171 | 
            
              | Article: Fortschritte in der Floristik der Schweizer Flora (Gefässpflanzen). 60. Folge (Canton de Genève) | 191 |