Ernest Thorp (Curator of the Durban Botanic Gardens 1950-1975) was the main driving force behind starting the Gardens’ orchid collection. The Ernest Thorp Orchid Display House was named in his honour in 1962. The collection comprises over 8000 plants in more than 75 natural and man-made genera and consists of species and hybrids, which are grown in large shade houses providing intermediate conditions with provision made for the warmer growing orchids.
Cattleyas represent the major part of the collection, from species rare in nature to modern hybrids. The Dendrobiumcollection comprises about 1000 plants and covers the six main groups. The other major genera represented are: Vanda, Phalaenopsis, Oncidium and Miltonia. The flowering plants are showcased in the Display House together with the colourful bromeliads.
The Gardens is expanding its collection of Madagascan and African orchids and these species will be grown as part of a conservation initiative, with a programme to reproduce threatened species from seed and tissue culture.
Cycads are the world’s most threatened group of organisms (SANBI; 2010). The Durban Botanic Gardens boasts the rarest cycad collection in the world which it has been curating since its inception in 1849.
Cycads are the oldest living seed plants and have survived three mass extinction events in the earth's history but they are facing a growing threat of extinction. The global conservation assessment of 308 cycad species shows that their status has declined from 53% threatened in 2003 to 62% threatened in 2010.
Wood’s Cycad (Encephalartoswoodii) is the Gardens’ most significant example and is reputed to be the world’s rarest plant. Today it can be found growing happily near the old reservoir. The Gardens cycad collection includes a good representation of South African, Central African, South American, Asian and Australasian species.
The Gardens has a fine collection of over 860 palms that belong to 130 species in 58 genera.
Globally there exist approximately 2800 species in over 200 genera
In Southern Africa there are five species: Borassus Palm (Borassus aethiopicum), iLala Palm (Hyphaene coriacea), Pondo Coconut Palm (Jubaeopsis caffra), Wild Date Palm (Phoenix reclinata) and Kosi Palm (Raphia australis). Palms are often regarded as the Princes of the Plant Kingdom.
There is a centenarian iLala Palm (Hyphaene coriacea) in the Gardens that is more than 150 years old. According to Medley Wood the male specimen was planted by Mark McKen in 1867.
The Durban Botanic Gardens also boasts an impressive arboretum, having a rich, living collection of woody trees from all over the world.
The Gardens has indigenous and exotic trees such as Centenarian trees (more than a hundred years old), fruit bearing trees (Mango), ornamental trees (Yellow Delonix regia), medicinal trees (Pepperbark), religious trees (Peepul Tree), fragrance (Frangipani),flavourful trees (Clove tree), and timber trees (Balsam)
The Buffalo Thorn (Ziziphus mucronata), for example, is more than 160 years old and was part of the original indigenous KwaZulu Natal coastal dune forest. “Evidently the last survivor of the original Berea forest that clothed the site before the Gardens moved here in 1851, so over 160 years old, and a magnificent tree.” (Dr Hugh Glen; 2013). It can be found near the old reservoir at the top of the Gardens.