Specializations
The botanical gardens of The Netherlands collectively manage the National Plant Collection. The Hortus has specialized in a few plant groups and thus contributes to the preservation of this unique collection. The gardens have united to form the Stichting Nationale Plantencollectie (SNP; National Plant Collection Foundation).
The specializations of the Hortus are:
South African plants
Ships of the Dutch East India Company (Verenigde Oost-Indische Compagnie; VOC) brought the first South African plants to Amsterdam. Many important ornamental and cut flowers reached Amsterdam from South Africa in this way, including the scented geranium (Pelargonium), Clivia, African lily (Agapanthus), and Gerbera. You will find some of the South African collection in the subtropical section of the Three-climate greenhouse: for example, the Cape 'Fijnbos' with its 'suikerbossies' (Protea) and silver trees (Leucadendron). Species from Namaqualand can be found in the desert section: the quiver trees (Aloe dichotoma) and Welwitschia ('tweeblaarkanniedood' = two-leaves cannot die, Welwitschia mirabilis).
Palms
You will find palm trees all over the Hortus. This is not surprising since palms grow in different climates. There are at least 2,500 species of palm trees worldwide. Some are hardy: they grow in the Outdoor garden of the Hortus. Most, however, are kept in the greenhouses, in particular in the tropical section of the three-climate greenhouse.
Carnivorous plants
Carnivorous plants grow in very nutrient-poor environments. In order to obtain enough nutrients, these plants have developed an exceptional characteristic: they catch live insects and digest them. People are often fascinated by the unusual capture mechanisms of carnivorous plants: ranging from sticky traps to 'bear' traps to liquid-filled pitchers that the insects drown in. Carnivorous plants are cultivated and sold on a large scale. This is good, because in nature a number of species are seriously threatened. Some carnivorous plants in the Hortus come from Australia and South Africa and are grown in special bogs in the subtropical part of the three-climate greenhouse. The hardy species have been put in a special bed near the tropical greenhouse.
Cycads
This group of primitive plants evolved more that 300 million years ago - long before the Age of Dinosaurs. Present-day cycad species however, emerged from their ancient ancestors 'only' 12 to 5 milion years ago. Today, cycads are on the endangered plant list and are protected worldwide. The Hortus contributes to the conservation of cycads by cultivating and propagating the plants and informing the public about the necessity of plant protection. Cycads can be found throughout the Hortus, from the terrace to the greenhouses. The largest and oldest specimens can be found in the monumental palmhouse, including the more than 300-year-old Eastern cape giant cycad (Encephalartos altensteinii) and the very rare Encephalartos woodii.
Conservatory plants
Conservatory plants are a specialization of the Hortus. In the past, these plants were grown outside in the summer and brought into 'an orangery' in the winter. The tall doors of the Orangery, now a beautiful museum café, are a reminder of those days. Today, the conservatory plants overwinter in the greenhouses. A few examples of the Hortus' - often old - conservatory plants are lemons (Citrus) and the olive (Olea europea).
Historic herb garden
Herbs formed the essence of the plant collection when the Hortus was founded in 1638 as the Hortus Medicus. In the Snippendaal garden, you will see a number of herb species that were used in the 17th century for education and research by doctors and pharmacists. Today, there is again a great deal of interest in medicinal plants.
