Adenium is succulent…
So does euphorbia, sansevieria, dorstenia, pachypodium, begonia, and of course, cacti
From Wikipedia, the free encyclopedia
Species: A. obesum
Adenium is a genus of flowering plants in the family Apocynaceae, containing a single species, Adenium obesum, also known as Sabi Star, Kudu or Desert-rose. It is native to tropical and subtropical eastern and southern Africa and Arabia.
It is an evergreen succulent shrub in tropical climates and semi-deciduous to deciduous in colder climates, is also dependant on the particular species. Growing to 1-3 m in height, with pachycaul stems and a stout, swollen basal caudex. The leaves are spirally arranged, clustered toward the tips of the shoots, simple entire, leathery in texture, 5-15 cm long and 1-8 cm broad. The flowers are tubular, 2-5 cm long, with the outer portion 4-6 cm diameter with five petals, resembling those of other related genera such as Plumeria and Nerium. The flowers tend to red and pink, often with a whitish blush outward of the throat.
Several regional subspecies occur:
- Adenium obesum subsp. boehmianum. Namibia, Angola.
- Adenium obesum subsp. obesum. Arabia.
- Adenium obesum subsp. oleifolium. South Africa, Botswana.
- Adenium obesum subsp. socotranum. Socotra.
- Adenium obesum subsp. somalense. Eastern Africa.
- Adenium obesum subsp. swazicum. Eastern South Africa.
- Adenium Arabicum subsp. Arabicum. Thailand.
- Adenium Arabicum subsp. Thai Socotranum. Thailand.
Cultivation and uses
Adenium is a popular houseplant in temperate regions. It requires a sunny location and a minimum indoor temperature in winter of 10°C. It thrives on a xeric watering regime as required by cacti. Adenium is typically propagated by seed or stem cuttings. The numerous hybrids are propagated mainly by grafting onto seedling rootstock. While plants grown from seed are more likely to have the swollen caudex at a young age, with time many cutting-grown plants cannot be distinguished from seedlings.
The plant exudes a highly toxic sap which is used by some peoples, such as the Akie in Tanzania, to coat arrow-tips for hunting.
Due to its resemblance to plumeria, and the fact that it was introduced to the Philippines from Bangkok, Thailand, the plant was also called as Bangkok kalachuchi in the Philippines.
Succulent plants, also known as succulents or fat plants, are water-retaining plants adapted to arid climate or soil conditions. Succulent plants store water in their leaves, stems and/or roots. The storage of water often gives succulent plants a more swollen or fleshy appearance than other plants, also known as succulence. In addition to succulence, succulent plants variously have other water-saving features. These may include:
- Crassulacean Acid Metabolism to minimize water loss
- Absent, reduced, or cylindrical to spherical leaves
- reduction in the number of stomata
- stems, rather than leaves, as the main site of photosynthesis
- a 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 reduce water loss via the creation of a humid microhabitat around the plant and a reduction in air movement near the surface of the plant.
Many succulents come from the dry areas of the tropics and subtropics, such as steppes, semi-desert and desert. High temperatures and low precipitation force plants to collect and store water in order to survive long dry periods. Succulents also occur as epiphytes, as such they have limited or no contact with the ground, and are dependent on their ability to store water. Succulents also occur as inhabitants of sea coasts, or salt pans which are exposed to high levels of dissolved minerals.
The best known succulents are cacti (family: Cactaceae). Virtually all cacti are succulents, but many succulents are not cacti.
Crassulacean acid metabolism
The Pineapple is a CAM plant
Crassulacean acid metabolism, also known as CAM photosynthesis, is an elaborate carbon fixation pathway in some plants. These plants fix carbon dioxide (CO2) during the night, storing it as the four carbon sugar malate. The CO2 is released during the day, where it is concentrated around the enzyme RuBisCO, increasing the efficiency of photosynthesis. The CAM pathway allows stomata to remain shut during the day; therefore it is especially common in plants adapted to arid conditions.
Overview of CAM: a two-part cycle
CAM is a mechanism whereby CO2 is concentrated around RuBisCO by day, while the enzyme is operating at peak capacity. This concentration of CO2 increases RuBisCO’s efficiency, as it is prone to operate in the “reverse” direction via photorespiration – utilising oxygen to break down the reaction products the plant would rather it was producing. It differs from C4 metabolism, which spatially concentrates CO2 around RuBisCO.
CAM plants open their stomata during the cooler and more humid night-time hours, permitting the uptake of carbon dioxide with the minimum water loss.
The carbon dioxide is converted to soluble molecules, which can be readily stored by the plant at a sensible concentration.
The precise chemical pathway involves a three-carbon compound phosphoenolpyruvate (PEP), to which a CO2 molecule is added via carboxylation – forming a new molecule, oxaloacetate. This is then reduced, forming malate. Oxaloacetate and malate are built around a skeleton of four carbons – hence the term C4. Malate can be readily stored by the plant in vacuoles within individual cells.
Malate can be broken down on demand, releasing a molecule of CO2 as it is converted to pyruvate. The pyruvate can be phosphorylated (i.e. have a phosphate group added by the “energy carrier” ATP) to regenerate the PEP with which we started, ready to be spurred into action the next night. But it is the release of CO2 that makes the cycle worth the plant’s while. It is directed to the stroma of chloroplasts: the sites at which photosynthesis is most active. There, it is provided to RuBisCO in great concentrations, increasing the efficiency of the molecule, and therefore producing more sugars per unit photosynthesis.
A great deal of energy is expended during CAM by the production and subsequent destruction of malate. This is in part countered by the increased efficiency of RuBisCO, but the more important benefit to the plant is the ability to leave leaf stomata closed during the day. CAM plants are most common in arid environments, where water comes at a premium. Being able to keep stomata closed during the hottest and driest part of the day reduces the loss of water through evapotranspiration, allowing CAM plants to grow in environments that would otherwise be far too dry.
How to spot a CAM plant
CAM can be considered an adaptation to arid conditions. CAM plants often display other xerophytic characters, such as thick, reduced leaves with a low surface-area-to-volume ratio; thick cuticle; and stomata sunken into pits. Some shed their leaves during the dry season; others (the succulents) store water in vacuoles.
CAM plants are not only good at retaining water, but use nitrogen very efficiently. However, due to their stomata being closed by day, they are less efficient at CO2 absorption. This limits the amount of carbon they have available for growth.
Families and genera
Plant families and genera in which succulent species occur are listed below.
- Agavaceae: Agave, Beschorneria, Chlorophytum, Furcraea, Hesperaloe, Hesperoyucca, Yucca
- Aizoaceae: Acrodon, Aloinopsis, Amoebophyllum, Amphibolia, Antegibbaeum, Apatesia, Aptenia, Arenifera, Argyroderma, Aridaria, Astridia, Bergeranthus, Berrisfordia, Braunsia, Brownanthus, Calamophyllum, Carpobrotus, Carruanthus, Caryotophora, Cephalophyllum, Cerochlamys, Chasmatophyllum, Cheiridopsis, Conicosia, Conophytum, Cylindrophyllum, Dactylopsis, Delosperma, Dicrocaulon, Dinteranthus, Dorotheanthus, Dracophilus, Drosanthemum, Eberlanzia, Ebracteola, Ectotropis, Enarganthe, Erepsia, Esterhuysenia, Eurystigma, Faucaria, Fenestraria, Frithia, Gibbaeum, Glottiphyllum, Halenbergia, Hereroa, Herrea, Herreanthus, Hydrodea, Hymenogyne, Imitaria, Jacobsenia, Juttadinteria, Kensitia, Khadia, Lampranthus, Lapidaria, Leipoldtia, Lithops, Machairophyllum, Malephora, Maughaniella, Mesembryanthemum, Mestoklama, Meyerophytum, Micropterum, Mimetophytum, Mitrophyllum, Monilaria, Muiria, Namaquanthus, Namibia, Nanathus, Nelia, Neohenricia, Neorhine, Nycteranthus, Octopoma, Odontophorus, Oophytum, Ophthalmophyllum, Orthopterum, Oscularia, Ottosonderia, Pherelobus, Platythyra, Pleiospilos, Polymita, Prenia, Psammophora, Psicaulon, Rabiea, Rhinephyllum, Rhombophyllum, Ruschia, Ruschianthemum, Ruschianthus, Saphesia, Sceletium, Schwantesia, Scopologena, Semnanthe, Skiatophytum, Smicrostigma, Sphalmanthus, Stayneria, Stomatium, Synaptophyllum, Titanopsis, Trichodiadema, Vanheerea, Vanzijlia, Wooleya, Zeuktophyllum
- Amaranthaceae: Arthraerva, Salicornia
- Amaryllidaceae: Boophane, Brunsvigia, Cyrtanthus, Haemanthus, Rauhia
- Anacardiaceae: Operculicaria, Pachycormus
- Apiaceae: Steganotaenia
- Apocynaceae: Adenium, Mandevilla, Pachypodium, Plumeria
- subfamily Asclepiadoideae (syn. Asclepiadaceae): Absolmsia, Asclepias, Aspidoglossum, Aspidonepsis, Baynesia, Brachystelma, Caralluma, Ceropegia, Cibirhiza, Cynanchum, Dischidia, Dischidiopsis, Duvalia, Duvaliandra, Echidnopsis, Edithcolea, Fanninia, Fockea, Glossostelma, Hoodia, Hoya, Huernia, Huerniopsis, Ischnolepis, Larryleachia, Lavrania, Marsdenia, Matelea, Miraglossum, Notechidnopsis, Odontostelma, Ophionella, Orbea, Orbeanthus, Pachycarpus, Pectinaria, Petopentia, Piaranthus, Pseudolithos, Quaqua, Raphionacme, Rhytidocaulon, Riocreuxia, Sarcorrhiza, Sarcostemma, Schizoglossum, Schlechterella, Stapelia, Stapelianthus, Stapeliopsis, Stathmostelma, Stenostelma, Stomatostemma, Tavaresia, Trachycalymma, Tridentea, Tromotriche, White-sloanea, Xysmalobium
- Araceae: Zamioculcas
- Araliaceae: Cussonia
- Asparagaceae: Myrsiphyllum
- Asphodelaceae: Aloe, Astroloba, Bulbine, Chortolirion, Gasteria, Haworthia, Poellnitzia, Trachyandra
- Asteraceae: Baeriopsis, Coulterella, Crassocephalum, Didelta, Gynura, Osteospermum, Othonna, Polyachyrus, Pteronia, Senecio
- Balsaminaceae: Impatiens
- Basellaceae: Anredera, Basella
- Begoniaceae: Begonia
- Bombaceae: Adansonia, Cavanillesia, Ceiba, Pseudobombax
- Brassicaceae: Heliophila, Lepidium
- Bromeliaceae: Abromeitiella
- Burseraceae: Beiselia, Bursea, Commiphora
- 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, Leocereus, Lepismium, Leptocereus, Leuchtenbergia, Lophophora, Maihuenia, Malacocarpus, Mammillaria, Mammilloydia, Matucana, Melocactus, Micranthocereus, Mila, Monvillea, Myrtillocactus, Neobuxbaumia, Neolloydia, Neoraimondia, Neowerdermannia, Obregonia, Opuntia, Oreocereus, Oroya, Ortegocactus, Pachycereus, Parodia, Pediocactus, Pelecyphora, Peniocereus, Pereskia, Pereskiopsis, Pilosocereus, Polaskia, Praecereus, Pseudoacanthocereus, Pseudorhipsalis, Pterocactus, Pygmaeocereus, Quiabentia, Rauhocereus, Rebutia, Rhipsalis, Samaipaticereus, Schlumbergera, Sclerocactus, Selenicereus, Stenocactus, Stenocereus, Stephanocereus, Stetsonia, Strombocactus, Tacinga, Thelocactus, Turbinicarpus, Uebelmannia, Weberbauerocereus, Weberocereus, Yungasocereus
- Campanulaceae: Brighamia
- Capparidaceae: Maerua
- Caricaceae: Carica, Jacarathia
- Commelinaceae: Aneilema, Callisia, Cyanotis, Tradescantia, Tripogandra
- Convolvulaceae: Ipomea, Sictocardia, Turbina
- Crassulaceae: Adromischus, Aeonium, Afrovivella, Aichryson, Cotyledon, Crassula, Cremnophila, Cremnosedum, Dudleya, Echeveria, Graptopetalum, Hylotelephium, Hypagophytum, Kalanchoe, Lenophyllum, Meterostachys, Monanthes, Orostachys, Pachyphytum, Perrierosedum, Phedimus, Pistorinia, Prometheum, Pseudosedum, Rhodiola, Rosularia, Sedella, Sedum, Sempervivum, Sinocrassula, Thompsonella, Tylecodon, Umbilicus, Villadia
- Cucurbitaceae: Apodanthera, Brandegea, Cephalopentandra, Ceratosanthes, Citrullus, Coccinia, Corallocarpus, Cucumella, Cucumis, Cucurbita, Cyclantheropsis, Dendrosicyos, Doyera, Eureindra, Fevillea, Gerrandanthus, Gynostemma, Halosicyos, Ibervilla, Kedostris, Marah, Momordica, Neoalsomitra, Odosicyos, Parasicyos, Syrigia, Telfairia, Trochomeria, Trochomeriopsis, Tumamoca, Xerosicyos, Zehneria, Zygosicyos
- Didiereaceae: Alluaudia, Alluaudiopsis, Decaria, Didierea
- Dioscoreaceae: Dioscorea
- Doryanthaceae: Doryanthes
- Ericaceae: Sphyrospermum
- Eriospermaceae: Eriospermum
- Euphorbiaceae: Cnidoscolus, Euphorbia, Jatropha
- Fabaceae: Delonix, Dolichos, Erythrina, Neorautanenia, Pachyrhizus, Tylosema
- Fouquieriaceae: Fouquieria
- Geraniaceae: Monsonia, Pelargonium
- Gesneriaceae: Aeschynanthus, Alsobia, Chirita, Codonanthe, Columnea, Nematanthus, Sinningia, Streptocarpus
- Hyacinthaceae: Albuca, Bowiea, Dipcadi, Drimia, Hyacinthus, Lachenalia, Ledebouria, Litanthus, Massonia, Ornithogalum, Rhadamanthus, Rhodocodon, Schizobasis, Urginea, Whiteheadia
- Icacinaceae: Pyrenacantha
- Lamiaceae: Aeollanthus, Dauphinea, Perrierastrum, Plectranthus, Solenostemon, Tetradenia, Thorncroftia
- Loasaceae: Schismocarpus
- Loranthaceae: Tapinanthus
- Melastomataceae: Medinilla
- Meliaceae: Entandrophragma
- Menispermaceae: Chasmanthera, Stephania, Tinospora
- Moraceae: Dorstenia, Ficus
- Moringaceae: Moringa
- Nolanace ae: Nolana
- Nolinaceae: Beaucarnea, Calibanus, Dasylirion, Nolina
- Orchidaceae subfamily Epidendroideae Phalaenopsis
- Oxalidaceae: Oxalis
- Passifloraceae: Adenia
- Pedaliaceae: Pterodiscus, Sesamothamnus, Uncarina
- Phyllanthaceae: Phyllanthus
- Phytolaccaceae: Phytolacca
- Piperaceae: Peperomia
- Portulacaceae: Amphipetalum, Anacampseros, Avonia, Calyptrotheca, Ceraria, Cistanthe, Dendroportulaca, Grahamia, Lewisia, Parakeelya, Portulaca, Portulacaria, Schreiteria, Talinella, Talinum
- Rubiaceae: Anthorrhiza, Hydnophythum, Hydrophylax, Myrmecodia, Myrmephythum, Phylohydrax, Squamellaria
- Ruscaceae: Cordyline, Dracaena, Sansevieria
- Sapindaceae: Erythrophysa
- Sterculiaceae: Brachychiton, Sterculia
- Urticaceae: Laportea, Obertia, Pilea, Sarcopilea
- Viscaceae: Viscum
- Vitaceae: Cissus, Cyphostemma
- Xanthorrhoeaceae: Xanthorrhoea
For some families, most members are succulent; for example the Cactaceae, Agavaceae, Aizoaceae, and Crassulaceae.