Succulent

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. Other sources exclude roots as in the definition "a plant with thick, fleshy and swollen stems and/or leaves, adapted to dry environments". The difference affects the relationship between succulents and "geophytes"–plants that survive unfavorable seasons as a resting bud on an underground organ. 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. Nor are all succulents xerophytes, as plants such as Crassula helmsii are both succulent and aquatic. ]] 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. Many books covering the cultivation of these plants include "cacti (cactus) and succulents" as the title or part of the title. In botanical terminology, cacti are succulents, 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. 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. Species with intermediate characteristics such as somewhat fleshy leaves or stems may be described as semi-succulent. Horticulturists often follow commercial conventions and may exclude other groups of plants such as bromeliads, that scientifically are considered succulents. A practical horticultural definition has become "a succulent plant is any desert plant that a succulent plant collector wishes to grow", without any consideration of scientific classifications. Commercial presentations of "succulent" plants will present those that customers commonly identify as such. Plants offered commercially then as "succulents", such as hen and chicks, will less often include geophytes, in which the swollen storage organ is wholly underground, but will include plants with a caudex, that is a swollen above-ground organ at soil level, formed from a stem, a root, or both.

, from the Jardin botanique d'Èze, France]] 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., ) * very impervious outer cuticle (skin) * fast wound sealing and healing * mucilaginous substances, which retain water abundantly

There is a thriving illegal trade in cacti and succulents. 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. 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.

: Pachypodium lealii, stem succulent]] : Haworthia arachnoidea, leaf succulent]] : Astroloba tenax, leaf succulent]] : Rebutia muscula, stem succulent]] : Crassula ovata, stem and leaf succulent]] : Euphorbia obesa ssp. symmetrica, stem succulent]] : stem, woody succulent]] : Adansonia digitata, stem succulent]] : Moringa ovalifolia, stem succulent]] : Beaucarnea recurvata, stem succulent]] : Dracaena draco, stem succulent]] ]] ]] ]] ]] There are approximately sixty different plant families that contain succulents. Plant orders, families, and genera in which succulent species occur are listed below. Order Alismatales * Araceae: Zamioculcas, Synandrospadix, Philodendron martianum, Dracontium Order Apiales * Apiaceae: Azorella, Crithmum * Araliaceae: Cussonia Order Arecales (also called Principes) * Arecaceae (also called Palmae) Jubaea 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 ** Convallarioideae: Beaucarnea, Calibanus, Dasylirion, Dracaena, Nolina ** Scilloideae (Hyacinthaceae): Albuca, Bowiea, Daubenya, Drimia, Eucomis, Lachenalia, Ledebouria, Massonia, Muscari, Ornithogalum, Scilla, Urginea, Veltheimia * Doryanthaceae: Doryanthes * Orchidaceae: Acampe, Aerangis, Ansellia, Bolusiella, Bulbophyllum, 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 * Asteraceae: Arctotheca, Baeriopsis, Chrysanthemoides, Coulterella, Crassocephalum, Curio, Delairea, Didelta, Emilia, Eremothamnus, Gymnodiscus, Gynura, Hillardiella (geophyte), Lopholaena, Monoculus, Nidorella, Osteospermum, Othonna (succulents and succulent geophytes), Phaneroglossa, Poecilolepis, Polyachyrus, Pteronia, Senecio, Solanecio, Tripteris * Campanulaceae: 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 Aizooideae: Acrosanthes, Aizoanthemum, Aizoon, Galenia, Gunniopsis, Plinthus, Tetragonia ** subfamily Mesembryanthemoideae (syn. Mesembryanthemaceae): Aptenia (synonym of Mesembryanthemum), 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 Dorotheantheae: Aethephyllum Cleretum Dorotheanthus *** tribe Ruschiae: Acrodon, Aloinopsis, Amphibolia, Antegibbaeum, Antimima, Arenifera, Argyroderma, Astridia, Bergeranthus, Bijlia, Braunsia, Brianhuntleya, Carpobrotus, Carruanthus, Cephalophyllum, Cerochlamys, Chasmatophyllum, Cheiridopsis, Circandra, Conophytum, Corpuscularia, Cylindrophyllum, Delosperma, Dicrocaulon, Didymaotus, Dinteranthus, Diplosoma, Disphyma, Dracophilus, Drosanthemum, Eberlanzia, Ebracteola, Enarganthe, Erepsia, Esterhuysenia, Faucaria, Fenestraria, Frithia, Gibbaeum, Glottiphyllum, Hallianthus, Hereroa, Ihlenfeldtia, Imitaria, Jacobsenia, Jensenobotrya, Jordaaniella, Juttadinteria, Khadia, Lampranthus, 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, Psammophora, Rabiea, Rhinephyllum, Rhombophyllum, Ruschia, Ruschianthemum, Ruschianthus, Schlechteranthus, Schwantesia, Scopelogena, Smicrostigma, Stayneria, Stoeberia, Stomatium, Tanquana Titanopsis, Trichodiadema, Vanheerdea, Vanzijlia, Vlokia, Wooleya, Zeuktophyllum ** subfamily Sesuvioideae: Cypselea, Sesuvium, Trianthema, Tribulocarpus, Zaleya * Amaranthaceae: ** subfamily Amaranthoideae: Arthraerva ** subfamily Chenopodioideae (family Chenopodiaceae):) Atriplex, Chenopodium, Dissocarpus, Einadia, Enchylaena, Eremophea, Halopeplis, Maireana, Malacocera, Neobassia, Osteocarpum, Rhagodia, Roycea, Halosarcia, Salicornia, Salsola, Sarcocornia, Sclerochlamys, Sclerolaena, Suaeda, Tecticornia, Threlkeldia * Anacampserotaceae: Anacampseros, Avonia, Grahamia * Basellaceae: Anredera, Basella * Cactaceae: Acanthocalycium, Acanthocereus, Ariocarpus, Armatocereus, Arrojadoa, Arthrocereus, Astrophytum, Austrocactus, Aztekium, Bergerocactus, Blossfeldia, Brachycereus, Browningia, Brasilicereus, Calymmanthium, Carnegiea, Cephalocereus, Cephalocleistocactus, Cereus, Cintia, Cipocereus, Cleistocactus, Coleocephalocereus, Copiapoa, Corryocactus, Coryphantha, Dendrocereus, Denmoza, Discocactus, Disocactus, Echinocactus, Echinocereus, Echinopsis, Epiphyllum, Epithelantha, Eriosyce, Escobaria, Escontria, Espostoa, Espostoopsis, Eulychnia, Facheiroa, Ferocactus, Frailea, Geohintonia, Gymnocalycium, Haageocereus, Harrisia, Hatiora, Hylocereus, Jasminocereus, Lasiocereus, Lepismium, Leptocereus, Leuchtenbergia, Lophophora, Maihuenia, Mammillaria, Matucana, Melocactus, Micranthocereus, Mila, Monvillea, Myrtillocactus, Neobuxbaumia, Neoraimondia, Neowerdermannia, Obregonia, Opuntia, Cylindropuntia, Oreocereus, Oroya, Ortegocactus, Pachycereus, Parodia, Pediocactus, Pelecyphora, Peniocereus, Pereskia, Pereskiopsis, Pilosocereus, Polaskia, Praecereus, Pseudoacanthocereus, Pseudorhipsalis, Pterocactus, Pygmaeocereus, Quiabentia, Rauhocereus, Rebutia, Rhipsalis, Schlumbergera, Sclerocactus, Selenicereus, Stenocactus, Stenocereus, Stephanocereus, Stetsonia, Strombocactus, Tacinga, Thelocactus, Trichocereus Turbinicarpus, Uebelmannia, Weberbauerocereus, Weberocereus * Didiereaceae: Alluaudia, Alluaudiopsis, Calyptrotheca, Decarya, Didierea, Portulacaria * Molluginaceae: Hypertelis * Montiaceae: Cistanthe, Calandrinia, Erocallis, Lewisia, Parakeelya, Phemeranthus, Thingia * Phytolaccaceae: Phytolacca * Portulacaceae: Portulaca * Talinaceae: Amphipetalum, Talinella, Talinum Order Commelinales * Commelinaceae: Aneilema, Callisia, Cyanotis, Tradescantia, Tripogandra Order Cornales * Loasaceae: Schismocarpus Order Cucurbitales * Begoniaceae: Begonia * Cucurbitaceae: Acanthosicyos, Apodanthera, Brandegea, Cephalopentandra, Ceratosanthes, Citrullus, Coccinia, Corallocarpus, Cucumella, Cucumis, Cucurbita, Cyclantheropsis, Dactyliandra, Dendrosicyos, Doyera, Eureindra, Fevillea, Gerrardanthus, Gynostemma, Halosicyos, Ibervillea, Kedostris, Lagenaria, Marah, Momordica, Neoalsomitra, Odosicyos, Parasicyos, Syrigia, Telfairia, Trochomeria, Trochomeriopsis, Tumamoca, Xerosicyos, Zehneria, Zygosicyos Order Dioscoreales * Dioscoreaceae: Dioscorea Order Ericales * Balsaminaceae: Impatiens * Ericaceae: Sphyrospermum * Fouquieriaceae: Fouquieria Order Fabales * Fabaceae: Delonix, Dolichos, Erythrina, Lotononis, Lupinus, Neorautanenia, Pachyrhizus, Tylosema Order Filicales * Polypodiaceae: Drymoglossum niphoboloides, Lecanopteris carnosa Order Gentianales * Apocynaceae: Adenium, Mandevilla, Pachypodium, Plumeria ** subfamily Asclepiadoideae (syn. Asclepiadaceae): Absolmsia, Australluma, Aspidoglossum, Aspidonepsis, Baynesia, Brachystelma, Ceropegia, Chlorocyathus, Cibirhiza, Cordylogyne, Cynanchum, Dischidia, Dischidiopsis, Duvaliandra, Eustegia, Fanninia, Fockea, Glossostelma, Hoya, Ischnolepis, Lavrania, Marsdenia, Miraglossum, Odontostelma, Ophionella, Orbeanthus, Pachycarpus, Parapodium, Periglossum, Petopentia, Raphionacme, Riocreuxia, Sarcorrhiza, Schizoglossum, Schlechterella, Stathmostelma, Stenostelma, Stomatostemma, Trachycalymma, Trichocaulon, Tylophora (now in Vincetoxicum), Woodia, Xysmalobium *** tribe Asclepiadeae: **** subtribe Asclepiadoideae: Asclepias, **** subtribe Gonolobinae: Matelea, *** tribe Maxillarieae: **** subtribe Lycastinae: Rudolfiella *** tribe Stapelieae: Angolluma, Caralluma, Desmidorchis, Duvalia, Echidnopsis, Edithcolea, Frerea, Hoodia, Huernia, Huerniopsis, Larryleachia, Notechidnopsis, Orbea (plant), Orbeopsis, Piaranthus, Pachycymbium, Pectinaria, Pseudolithos, Pseudopectinaria, Quaqua, Rhytidocaulon, Stapelia, Stapelianthus, Stapeliopsis, Tavaresia, Tridentea, Tromotriche, Whitesloanea ** subfamily Periplocoideae: *** tribe Cryptolepideae: Cryptolepis * 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 * Lamiaceae: Aeollanthus, Dauphinea, Perrierastrum, Plectranthus, Rotheca, Solenostemon, Tetradenia, Thorncroftia * Lentibulariaceae * Pedaliaceae: Holubia, Pterodiscus, Sesamothamnus, Uncarina Order Malpighiales * Euphorbiaceae: Cnidoscolus, Euphorbia, Jatropha, Monadenium, Pedilanthus, Synadenium * Passifloraceae: Adenia * Phyllanthaceae: Phyllanthus Order Malvales * Cochlospermaceae * Malvaceae: Adansonia, Cavanillesia, Ceiba, Pseudobombax ** subgroup Sterculiaceae: Brachychiton, Sterculia Order Myrtales * Melastomataceae: Medinilla Order Oxalidales * Oxalidaceae (geophytes): Oxalis Order Piperales * Piperaceae: Peperomia Order Poales * Bromeliaceae: Abromeitiella, Aechmea, Ananas, Catopsis, Connellia, Dyckia, Hechtia, Neoregelia, Puya, Tillandsia, Vriesea * Poaceae: Dregeochloa, Laobambos Order Ranunculales * Menispermaceae: Chasmanthera, Stephania, Tinospora Order Rosales * Moraceae: Dorstenia, Ficus * Urticaceae: Laportea, Obetia, Pilea, Pouzolzia, Sarcopilea Order Santalales * Loranthaceae: Actinanthella, Agelanthus, Erianthemum, Helixanthera, Moquiniella, Oncocalyx, Pedistylis, Plicosepalus, Septulina, Tapinanthus, Vanwykia * Viscaceae (syn. Santalaceae): Viscum Order Sapindales * Anacardiaceae: Operculicaria, Pachycormus * Burseraceae: Boswellia, Bursera, Commiphora * Meliaceae: Entandrophragma * Sapindaceae: Erythrophysa Order Saxifragales * Crassulaceae: Adromischus, Aeonium, Afrovivella,Aichryson, Cotyledon, Crassula, Cremnophila, Dudleya, Echeveria, Graptopetalum, Greenovia, Hylotelephium, Kalanchoe, Kungia, Lenophyllum, Meterostachys, Monanthes, Mucizonia, Orostachys, Pachyphytum, Perrierosedum, Petrosedum, Phedimus, Pistorinia, Prometheum, Pseudosedum, Rhodiola, Rosularia, Sedella, Sedum, Sempervivum, Sinocrassula, Thompsonella, Tylecodon, Umbilicus, Villadia * Saxifragaceae: Micranthes, Saxifraga Order Solanales * Convolvulaceae: Ipomoea, Merremia, Stictocardia, Turbina (plant) * Solanaceae: Nolana Order Vitales * Vitaceae: Cissus, Cyphostemma, Vitis Order Zygophyllales * Zygophyllaceae: Augea, Seetzenia, Zygophyllum (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 * Cheirolepidiaceae: 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: {|class="wikitable" ! 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 |-------------------------------------------------------------- |}

, Echeveria, and Crassula]] Succulents are favored as houseplants for their attractiveness and ease of care. They have been cultivated as houseplants since at least the 17th century. If properly potted, succulents require little maintenance to survive indoors. Succulents are very adaptable houseplants and will thrive in a range of indoor conditions. For most plant owners, over-watering and associated infections are the main cause of death in succulents. Succulents can be propagated in a number of ways, with vegetative propagation being the most common. This includes cuttings, where a few centimetres of the leafy stem is cut off and left to heal, forming a callus. Following a period of approximately seven days, roots may begin to develop. A second method is division consisting of uprooting an overgrown clump and pulling the stems and roots apart. 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. The vegetative propagation can be different according to the species.