![]() ![]() A parasite may be further classified into a holoparasite, one that lacks photosynthesis/chloroplasts and must attach to a host to survive and reproduce (e.g., Cuscuta, Orobanche, Balanophora), or a hemiparasite, a parasitic plant that is photosynthetic during at least part of its life cycle. Plant life form types denoting nutritional physiology include: saprophyte, a heterotrophic plant living off dead organic matter mycotroph, a usually achlorophyllous plant having an intimate contact with a fungus, from which it receives most of its nutrition and parasite, a plant feeding on another plant, dependent on it for all or part of its nutrition. Life form types include: therophyte, an annual plant geophyte, a perennial herb with underground perennating rootstocks such as bulbs, corms, rhizomes epiphyte, a plant growing on another plant, e.g., Tillandsia (Bromeliaceae) halophyte, a salt-adapted plant succulent, a plant with fleshy stems ( stem succulents, e.g., cacti) or leaves ( leaf succulents, e.g., members of Aizoaceae or Crassulaceae) and xerophyte, a plant adapted to live in a dry, generally hot environment. Plant life form denote aspects of their structure, life cycle, and physiology. Simpson, in Plant Systematics (Second Edition), 2010 Plant Life Form This is not only partly due to an imbalance of institutional resources between such regions, but also due to the fact that many of the botanic gardens in tropical and developing countries are younger institutions without the long history of development of many European countries, that has allowed the growth of extensive collections built up over decades, and sometimes centuries. The collections in most tropical and developing countries are significantly smaller than those in many temperate countries. The majority of collections are in Europe and North America (making up more than 50% of the total). The following broad categories are well represented worldwide in botanic garden ex situ collections:Īs Table 3 shows, the distribution of accessions in botanic gardens worldwide is uneven. It should be stressed, however, that this list is by no means complete and it should not be suggested that botanic gardens are either largely focused on such thematic collections, or that they do not maintain extensive collections of groups that fall outside of any of the categories listed. In some cases, botanic gardens concentrate on the development of their collections following particular thematic, taxonomic and geographical lines, including the broad categories outlined below. Many botanic gardens have also assumed special responsibilities for the cultivation of rare and endangered plants and other taxa of conservation importance. Over the past few decades there has been an increasing trend amongst botanic gardens to cultivate native plants from their own regions. Sutherland, in Encyclopedia of Biodiversity (Second Edition), 2013 Botanic Garden Collections ![]()
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