Succulent plant
In
Succulent plants may store water in various structures, such as
Succulents are not a
Definition
By definition, succulent plants are drought-resistant plants in which the leaves, stem, or roots have become more than usually fleshy by the development of water-storing tissue.[5] Other sources exclude roots as in the definition "a plant with thick, fleshy and swollen stems and/or leaves, adapted to dry environments".[6] The difference affects the relationship between succulents and "geophytes"–plants that survive unfavorable seasons as a resting bud on an underground organ.[7]
The underground organs, such as bulbs, corms, and tubers, are often fleshy with water-storing tissues. Thus, if roots are included in the definition, many geophytes would be classed as succulents. Plants adapted to living in dry environments such as succulents, are termed xerophytes. Not all xerophytes are succulents, since there are other ways of adapting to a shortage of water, e.g., by developing small leaves which may roll up or having leathery rather than succulent leaves.[8] Nor are all succulents xerophytes, as plants such as Crassula helmsii are both succulent and aquatic.[9] Succulents allow themselves to go a long ways without any or low water necessary.
Some who grow succulents as a hobby may use the term in a different way from botanists. In horticultural use, the term succulent regularly excludes cacti. For example, Jacobsen's three volume Handbook of Succulent Plants does not include cacti.[10] Many books covering the cultivation of these plants include "cacti (cactus) and succulents" as the title or part of the title.[11][12][13] In botanical terminology, cacti are succulents,[5] but not the reverse, as many succulent plants are not cacti. Cacti form a monophyletic group and apart from one species are native only to the New World, the Americas, but through parallel evolution similar looking plants in completely different families like the Apocynaceae evolved in the Old World.[citation needed]
A further difficulty for general identification is that plant families are neither succulent nor non-succulent and can contain both. In many genera and families, there is a continuous gradation from plants with thin leaves and normal stems to those with very clearly thickened and fleshy leaves or stems. The succulent characteristic becomes meaningless for dividing plants into genera and families. Different sources may classify the same species differently.[14] Species with intermediate characteristics such as somewhat fleshy leaves or stems may be described as semi-succulent.[15]
Horticulturists often follow commercial conventions and may exclude other groups of plants such as
Appearance
The storage of water often gives succulent plants a more swollen or fleshy appearance than other plants, a characteristic known as succulence. In addition to succulence, succulent plants variously have other water-saving features. These may include:
- crassulacean acid metabolism (CAM) to minimize water loss
- absent, reduced, or cylindrical-to-spherical leaves
- reduction in the number of stomata
- stems as the main site of photosynthesis, rather than leaves
- compact, reduced, cushion-like, columnar, or spherical growth form
- ribs enabling rapid increases in plant volume and decreasing surface area exposed to the sun
- waxy, hairy, or spiny outer surface to create a humid micro-habitat around the plant, which reduces air movement near the surface of the plant, and thereby reduces water loss and may create shade
- roots very near the surface of the soil, so they are able to take up moisture from very small showers or even from heavy dew
- ability to remain plump and full of water even with high internal temperatures (e.g., 52 °C or 126 °F)[19]
- very impervious outer cuticle (skin)[19]
- fast wound sealing and healing[20]
- mucilaginous substances, which retain water abundantly[19]
Habitat
Other than in
Australia, the world's driest inhabited continent, hosts very few native succulents due to the frequent and prolonged droughts[citation needed]. Even Africa, the continent with the most native succulents, does not host many of the plants in its most dry regions.[24] While succulents are unable to grow in these harshest of conditions, they are able to grow in conditions that are uninhabitable by other plants. In fact, many succulents are able to thrive in dry conditions, and some are able to last up to two years without water depending on their surroundings and adaptations.[25]
Occasionally, succulents may occur as epiphytes, growing on other plants with limited or no contact with the ground, and being dependent on their ability to store water and gaining nutrients by other means; it is seen in Tillandsia. Succulents also occur as inhabitants of sea coasts and dry lakes, which are exposed to high levels of dissolved minerals that are deadly to many other plant species. California is home to close to hundred succulent species that are native to the state, many of them live in coastal environments.[26] Potted succulents are able to grow in most indoor environments with minimal care.[27]
Conservation
There is a thriving illegal trade in cacti and succulents.[28][29] In South Africa, several species of succulent have been threatened with extinction due to poaching from the wild for the black market and mining related activities. The plants are mainly sold to collectors in Asian countries, where there has been a high demand for them.[30][22] Since 1974, it is illegal to be in possession of protected succulents such as the Conophytum without authorisation in the Western Cape and Northern Cape, the two South African provinces where they grow.[30]
Families and genera
This section includes a improve this section by introducing more precise citations. (September 2012) ) |
There are approximately sixty different plant families that contain succulents.[31] Plant orders, families, and genera in which succulent species occur are listed below.
Order Alismatales
Order Apiales
Order Arecales (also called Principes)
Order Asparagales
- Amaryllidaceae (geophytes): Amaryllis, Boophone, Clivia, Crinum, Cryptostephanus, Cyrtanthus, Haemanthus, Rauhia, Scadoxus, Stenomesson
- Asparagaceae
- Agavoideae: Agave, Beschorneria, Furcraea, Hesperaloe, Hesperoyucca, Manfreda, Polianthes, Yucca
- Lomandroideae: Cordyline
- Nolinoideae: Beaucarnea, Calibanus, Dasylirion, Dracaena, Nolina
- Scilloideae (Hyacinthaceae): Albuca, Bowiea, Daubenya, Drimia, Eucomis, Lachenalia, Ledebouria, Massonia, Ornithogalum, Scilla, Urginea, Veltheimia
- Doryanthaceae: Doryanthes
- Cirrhopetalum, Calanthe, Cyrtorchis, Dendrobium cucumerinum, Eulophia, Liparis, Oberonia, Oeceoclades, Polystachya, Tridactyle, Vanilla
- Asphodelaceae
- subfamily Asphodeloideae: Aloe (succulents and succulent geophytes), Astroloba, Tulista, × Astrolista, Bulbine (succulent geophytes, succulents, and geophytes), Bulbinella (geophyte), Chortolirion (succulent geophytes), Gasteria, Gonialoe, Haworthia, Trachyandra (succulent geophytes and succulents),
- subfamily Xanothorrhoeoidae: Xanthorrhoea
Order Asterales
- Tripteris
- Brighamia
Order Brassicales
- Brassicaceae: Heliophila, Lepidium
- Capparidaceae: Maerua
- Caricaceae: Carica, Jacarathia
- Moringaceae: Moringa
- Tiganophytaceae Tiganophyta karasense
Order Caryophyllales
- Aizoaceae: Corbichonia, Gisekia, Herreanthus, Limeum, Ophthalmophyllum, Saphesia
- subfamily
- subfamily Aridaria, Aspazoma, Brownanthus (synonym of Mesembryanthemum), Calamophyllum, Caulipsilon, Conophytum, Dactylopsis, Erepsia, Hameria, Hartmanthus, Hymenogyne, Marlothistela, Mesembryanthemum, Phiambolia, Phyllobolus, Prenia, Psilocaulon, Ruschiella, Sarozona, Synaptophyllum
- subfamily Ruschioideae:
- tribe Apatesieae: Apatesia, Carpanthea, Caryotophora, Conicosia, Hymenogyne, Saphesia, Skiatophytum
- tribe Dorotheanthus
- tribe Lapidaria (plant), Leipoldtia, Lithops, Machairophyllum, Malephora, Mestoklema, Meyerophytum, Mitrophyllum, Monilaria, Mossia, Muiria, Namaquanthus, Namibia, Nananthus, Nelia, Neohenricia, Octopoma, Odontophorus, Oophytum, Ophthalmophyllum, Orthopterum, Oscularia, Ottosonderia, Pleiospilos, Polymita, Psammophora, Rabiea, Rhinephyllum, Rhombophyllum, Ruschia, Ruschianthemum, Ruschianthus, Schlechteranthus, Schwantesia, Scopelogena, Smicrostigma, Stayneria, Stoeberia, Stomatium Tanquana Titanopsis, Trichodiadema, Vanheerdea, Vanzijlia, Vlokia, Wooleya, Zeuktophyllum
- subfamily
- Amaranthaceae:
- subfamily Amaranthoideae: Arthraerva
- subfamily Halosarcia, Salicornia, Salsola, Sarcocornia, Sclerochlamys, Sclerolaena, Suaeda, Tecticornia, Threlkeldia
- Basellaceae: Anredera, Basella
- Didiereaceae: Alluaudia, Alluaudiopsis, Decaria, Didierea
- Molluginaceae: Hypertelis
- Phytolaccaceae: Phytolacca
Order Commelinales
Order Cornales
Order Cucurbitales
- Begoniaceae: Begonia
- Cucurbitaceae: Acanthosicyos, Apodanthera, Brandegea, Cephalopentandra, Ceratosanthes, Citrullus, Coccinia, Corallocarpus, Cucumella, Cucumis, Cucurbita, Cyclantheropsis, Dactyliandra, Dendrosicyos, Doyera, Eureindra, Fevillea, Gerrandanthus, Gynostemma, Halosicyos, Ibervilla, Kedostris, Lagenaria, Marah, Momordica, Neoalsomitra, Odosicyos, Parasicyos, Syrigia, Telfairia, Trochomeria, Trochomeriopsis, Tumamoca, Xerosicyos, Zehneria, Zygosicyos
Order Dioscoreales
Order Ericales
- Balsaminaceae: Impatiens
- Ericaceae: Sphyrospermum
- Fouquieriaceae: Fouquieria
Order Fabales
Order
- Polypodiaceae Drymoglossum niphoboloides, Lecanopteris carnosa
Order Gentianales
- Apocynaceae: Adenium, Mandevilla, Pachypodium, Plumeria
- subfamily
- tribe Asclepiadeae:
- subtribe Asclepiadne: Asclepias,
- subtribe Gonolobinae: Matelea,
- tribe Maxillarieae:
- subtribe Lycastinae: Rudolfiella
- tribe Pachycymbium, Pectinaria, Pseudolithos, Pseudopectinaria, Quaqua, Rhytidocaulon, Stapelia, Stapelianthus, Stapeliopsis, Tavaresia, Tridentea, Tromotriche, Whitesloanea
- tribe
- subfamily Periplocoideae:
- tribe Cryptolepideae: Cryptolepis
- subfamily
- Rubiaceae: Anthorrhiza, Anthospermum, Hydnophytum, Hydrophylax, Myrmecodia, Myrmephytum, Phylohydrax, Squamellaria
Order Geraniales
- Geraniaceae: Monsonia, Pelargonium (succulents and geophytes), Sarcocaulon
Order Lamiales
- Gesneriaceae: Aeschynanthus, Alsobia, Chirita, Codonanthe, Columnea, Nematanthus, Sinningia, Streptocarpus
- Lentibulariaceae
Order Malpighiales
- Synadenium
- Passifloraceae: Adenia
- Phyllanthaceae: Phyllanthus
Order Malvales
- Cochlospermaceae
- Malvaceae: Adansonia, Cavanillesia, Ceiba, Pseudobombax
- subgroup Sterculiaceae: Brachychiton, Sterculia
Order Myrtales
Order Oxalidales
- Oxalidaceae (geophytes): Oxalis
Order Piperales
Order Poales
- Puya, Tillandsia, Vriesea
- Poaceae: Dregeochloa,[36] Laobambos[37]
Order Ranunculales
Order Rosales
Order Santalales
- Loranthaceae: Actinanthella, Agelanthus, Erianthemum, Helixanthera, Moquiniella, Oncocalyx, Pedistylis, Plicosepalus, Septulina, Tapinanthus, Vanwykia
- Viscaceae (syn. Santalaceae): Viscum
Order Sapindales
- Pachycormus
- Burseraceae: Boswellia, Bursera, Commiphora
- Meliaceae: Entandrophragma
- Sapindaceae: Erythrophysa
Order Saxifragales
- Mucizonia, Orostachys, Pachyphytum, Perrierosedum, Petrosedum, Phedimus, Pistorinia, Prometheum, Pseudosedum, Rhodiola, Rosularia, Sedella, Sedum, Sempervivum, Sinocrassula, Thompsonella, Tylecodon, Umbilicus, Villadia[38]
- Saxifragaceae: Micranthes, Saxifraga
Order Solanales
Order
Order Zygophyllales
(unplaced order)* Boraginaceae: Heliotropium (unplaced order)* Icacinaceae: Pyrenacantha (geophyte)
There also were some succulent gymnosperms (but extinct since the end of the Cretaceous):
Order Pinales
Frenelopsis, Pseudofrenelopsis, Suturovagina, Glenrosa
For some families and subfamilies, most members are succulent; for example the Cactaceae, Agavoideae, Aizoaceae, and Crassulaceae.
The table below shows the number of succulent species found in some families and their native habitat:[citation needed]
Family or subfamily | Succulent # | Modified parts | Distribution |
---|---|---|---|
Agavoideae | 300 | Leaf | North and Central America |
Cactaceae | 1600 | Stem (root, leaf) | The Americas |
Crassulaceae | 1300 | Leaf (root) | Worldwide |
Aizoaceae | 2000 | Leaf | Southern Africa, Oceania, Chile |
Apocynaceae | 500 | Stem | Africa, Arabia, India, Australia |
Asphodelaceae | 500+ | Leaf | Africa, Madagascar, Australia |
Didiereaceae | 11 | Stem | Madagascar ( endemic )
|
Euphorbiaceae | > 1000 | Stem or leaf or root | Australia, Africa, Madagascar, Asia, the Americas, Europe |
Portulacaceae | ~500 | Leaf and stem | The Americas, Australia, Africa |
Cheirolepidiaceae | 4, maybe more | Leaf | Worldwide, except Antarctica |
Cultivation
Succulents are favored as houseplants for their attractiveness and ease of care. They have been cultivated as houseplants since at least the 17th century.[39] If properly potted, succulents require little maintenance to survive indoors.[40] Succulents are very adaptable houseplants and will thrive in a range of indoor conditions.[41] For most plant owners, over-watering and associated infections are the main cause of death in succulents.[42]
Succulents can be propagated by different means. The most common is vegetative propagation. This includes cuttings where several inches of stem with leaves are cut and after healing, produce a callus. After a week or so, roots may grow. A second method is division consisting of uprooting an overgrown clump and pulling the stems and roots apart.[43]
A third method is propagation by leaf by allowing the formation of a callus. During this method, a bottom leaf is fully removed from the plant often by twisting or cutting. The leaf then dries out and a callus forms preventing the leaf from absorbing too much moisture and rotting. This method typically takes up to a few weeks to produce healthy roots that would eventually create new plants.[44] The vegetative propagation can be different according to the species.[45]
See also
References
- ^ Merriam-Webster: succulent, retrieved 2015-04-13
- PMID 28898660.
- ^ Jacobsen Handbook op.cit. Volume 3 P. 1259
- ^ Dimmitt, Mark. "The Tucson Cactus and Succulent Society". www.tucsoncactus.org. Archived from the original on 22 August 2017. Retrieved 5 February 2017.
- ^ a b Rowley 1980, p. 1
- ^ Beentje 2010, p. 116
- ^ a b Beentje 2010, p. 32
- ^ "xerophyte", Dictionary of Botany, 2001, retrieved 2012-09-23
- ^ "Crassula helmsii (aquatic plant, succulent)", Global Invasive Species Database, ISSG, April 15, 2010, retrieved 2012-09-23
- ^ Jacobsen 1960
- ^ Anderson 1999
- ^ Hecht 1994
- ^ Hewitt 1993
- ^ Rowley 1980, p. 2
- ISBN 978-2-8317-0390-9. Retrieved 18 May 2023.
- ^ Innes & Wall 1995
- ^ Martin & Chapman 1977
- ^ Martin & Chapman 1977, pp. 19–20
- ^ a b c Compton n.d.
- PMID 29441263.
- .
- ^ ISSN 0362-4331. Retrieved 2022-03-16.
- JSTOR 42788160.
- ^ "Succulents in their natural environment". November 2021.
- ^ "Cactuses and Succulents".
- ^ "California's Native Succulents".
- ^ "Succulent Care Tips". 17 April 2019.
- ISBN 978-1-5179-1399-1.)
{{cite book}}
: CS1 maint: date and year (link - ISSN 1073-0451.
- ^ a b "These tiny succulents are under siege from international crime rings". Animals. 2022-03-08. Archived from the original on March 8, 2022. Retrieved 2022-03-16.
- ^ "10 Things You Never Knew About Succulents". 16 September 2018.
- ^ "Apiaceae". succulent-plant.com. Retrieved 2018-02-07.
- ^ Plants of Southern Africa Archived 2017-07-28 at the Wayback Machine Retrieved on 2010-1-1
- ^ FloraBase – The Western Australian Flora Archived 1999-10-12 at the Wayback Machine Retrieved on 2010-1-1
- ^ Parakeelya. Archived 2013-07-03 at the Wayback Machine The Plant List.
- ^ Dregeochloa pumila. Archived 2016-03-04 at the Wayback Machine South African National Biodiversity Institute
- PMID 32913413.
- ^ "Crassulaceae Genera". Missouri Botanical Garden. Retrieved 2017-10-26.
- ^ Through England On a Side Saddle in the Time of William and Mary. London: Field & Tuer, The Leadenhall Press, E.C. 1888. p. 91.
- ^ Kramer, Jack (1977). Cacti and Other Succulents. New York: Abrams. p. 9.
- ^ Kramer, Jack (1977). Cacti and Other Succulents. New York: Abrams. p. 49.
- ^ SproutingIndoors (2020-06-13). "Succulent Root Rot: What it is and How to Treat it". Sprouting Indoors. Retrieved 2020-06-15.
- ^ "Propagating Succulents". 31 May 2013.
- ^ "Propagating Succulents". 31 May 2013.
- ^ Lee, Debra (2007). Designing with Succulents. Portland, Obregon: Timber Press. p. 133.
Bibliography
- Anderson, Miles (1999), Cacti and Succulents : Illustrated Encyclopedia, Oxford: Sebastian Kelly, ISBN 978-1-84081-253-4
- Beentje, Henk (2010), The Kew Plant Glossary, Richmond, Surrey: ISBN 978-1-84246-422-9
- Compton, R.H., ed. (n.d.), Our South African Flora, Cape Times Ltd, OCLC 222867742(publication date also given as 1930s or 1940s)
- Hecht, Hans (1994), Cacti & Succulents (p/b ed.), New York: Sterling, ISBN 978-0-8069-0549-5
- Hewitt, Terry (1993), The Complete Book of Cacti & Succulents, London: Covent Garden Books, ISBN 978-1-85605-402-7
- Innes, Clive & Wall, Bill (1995), Cacti, Succulents and Bromeliads, London: Cassell for the Royal Horticultural Society, ISBN 978-0-304-32076-9
- Jacobsen, Hermann (1960), A Handbook of Succulent Plants (Vols 1–3), Poole, Dorset: Blandford Press, ISBN 978-0-7137-0140-1
- Martin, Margaret J. & Chapman, Peter R. (1977), Succulents and their cultivation, London: Faber & Faber, ISBN 978-0-571-10221-1
- Rowley, Gordon D. (1980), Name that Succulent, Cheltenham, Glos.: Stanley Thornes, ISBN 978-0-85950-447-8