WHAT ARE CACTI AND SUCCULENTS?
Firstly …it is one cactus … and two or more cacti. Cacti is the plural of Cactus. And it is CACTUS……. NOT ‘CATCUS’ !
Succulents (which includes the Cactus family) have evolved a highly specialized anatomy to enable them to survive prolonged drought.
They store water in the fleshy ‘succulent’ tissue in their… Stems , Roots and Leaves
Stem succulents retain water in their round, tall or barrel shapes. These stems contain chlorophyll used in photosynthesis. They are often ribbed, like a concertina, allowing for expansion and contraction . Most Cacti are stem succulents. Caudiciform succulents (such as Adenium) fall into this description.
Root succulents store water underground in their tuberous swollen roots. This also reduces damage caused by fires and grazing animals
Leaf succulents describes most succulent plants which store water in their fleshy thick leaves which shrivel up in drought as water is drawn back toward the centre of the plant to resist extended drought when most leaves will be shed but the plant will recover and re-grow when rain falls again. Many leaf succulents have short stems, froming rosettes of overlapping leaves which help reduce evaporation from the plant and the soil beneath.
WHAT ELSE IS DIFFERENT? – SURFACES, SPINES + THORNS, FLOWERS, FRUITS AND SEEDS.
All succulents have thicker skins and fewer stomata (breathing holes) than the average plant. Local adaptations can be seen in high altitude, misty + foggy areas with little rainfall …..here plants with hairy surfaces survive by trapping moisture. Some have a waxy skin covered in a white, powder like bloom to diffuse bright light and reduce transpiration.
In coastal areas Cacti spines condense dew which drips on the soil. Woolly spines shield the plant from the fierce sun and protect from harsh winds. Cacti spines always grow from an Areole ( a modified bud from which shoots, flowers and spines grow.) Some leafless succulents (such as euphorbia) grow thorns directly from the plant tissue – these are modified flowers, stalks or buds. Only true Cacti have spines. Spines and thorns repel animals which would otherwise make a tasty meal of a defenseless plant. Some Cacti have fish-hook spines to grab onto passing cattle and relocate an offset when it falls elsewhere.
Flowers of Cacti are often brightly coloured to attract flying insects, but have little scent. Others are large, night-blooming flowers which release an intense, deep aroma to attract pollinating moths. Others are foul-smelling ‘carrion’ flowers to attract bats and rodents. Some have long, tubular flowers which can only be reached by the long beaks of hummingbirds. As a general rule the flowers of Cacti are far superior to those of ‘the other’ Succulents.
Succulent flowers, fruits and seeds are very diverse and are distributed by wind, water, insects, rodents and birds. Some plants have fleshy, sugary fruits and berries while others have ‘dust’ like seeds released from aged, woody pods that only open when rains fall. Euphorbia seed pods ‘explode’ when ripe to disperse 3 seeds. Cacti often produce long, silky petals which can grow many centimeters in a day. The flower neck is often covered in spines which helped to protect the bud while sat waiting for rains. Flowers are usually formed in early and mid summer – after the winter rest (when most of the flower formation occurs).
NATURAL HABITATS of succulent plants.
Contrary to popular belief, Cacti and Succulents do not inhabit only deserts. In fact, few plants survive in a true desert (with less than 25cm of annual rain). Most grow in semi-deserts (like Andalucia !) which have poor soil, sparse vegetation and rocky outcrops (not just pure sand!)
Rainfall is sometimes augmented by coastal mists or heavy dews. Young succulents grow under the shade of larger bushes or in rock crevices. Many can survive bush fires because of their compact, watery composition. Ranging from snow-clad alpine slopes (sedums and sempervivums), to arid windy plains, to humid jungles (epiphytes) …these plants are highly adapted to survive and do so because other, less robust plants simply cannot compete in that location.
DISCOVERY AND DISTRIBUTION of succulent plants. Cacti originate from the American continent
Succulents are native to Europe and the far east.
Exploration and trading over the last 5 centuries enables these plants to establish new habitats across the world.
In the late 15th centuryChristopher Columbus found weird and leafless plants in the west indies such as Melocactus and Opuntia, and presented them to Queen Isabella of Spain.Vasco da Gama found Aloes and Gasterias in South Africa
Spanish Missionaries colonized C and S America in the 15 – 17th centuries and sent plants back to Europe on their trading ships.
In the 17th century the Dutch East India Company shipped many plants to Holland and onward to The RBG at Kew.
Between 1777 and 1787 King Charles 3rd sponsored many plant-hunting expeditions to America.
In 1788 Captain Arthur Philip (founder of Sydney) introduced Opuntia cacti into Australia to establish a coccineal dye industy. However…..planting of these Opuntias is now ‘banned’ in Oz!
Thomas Bridges, Richard Bradley and Thomas Nuttal documented the widespread and highly variable characteristics of these plants. They made a start at classifying and describing the species know at that time, as did Carolus Linnaeus (who chose the word Kaktos (thistle plant) to name the Cactus Family. The Cactus BiBle is named The Cactaceae, a four volume masterpiece created by Britton and Rose in 1923. However, some of these plants are being renamed and reclassified as we speak due to the usefulness of laboratories able to decifer DNA of plants.
In the 1800’s noblemen across the world could afford to build heated greenhouses and established huge collections (plundering most of the plants from natural habitats). This created a higher price for these almost extinct curiosities and their value has remained ever since. Some hybrid Astrophytums sell for thousands of pounds - their value is reflected by rarity, and beauty. Over the last century, with worldwide travel becoming easier and cheaper, private collectors have plundered local populations because of the accuracy and detail of their location being proudly shown to all who cares. This was the boast of a collector – describing its location as proof. However- at a hundred pounds a plant the locals were easily motivated to collect every plants they could find in exchange for a foreigners money – a years wages could be earned in a few days by a ‘field’ collector and hence we are in this situation today …. Most cacti are extinct in their original habitat. Only the ugly, spikey or less desirable plants still survive to tell a tale.
It must be noted that man alone has not caused this near-exinct status of many plants – large grazing herds, land development, dams and reservoirs, climatic changes, pollution, occasional frost, and depletion of natural predators hasn’t helped the plight of these Plants. Most Cacti and Succulents are firmly contained in private and public Collections where they are better off cared for and the chances of propagation are vastly increased.
Worldwide export of endangered Cacti species from the Americas is now regulatd under CITES – an international law controlling the movement of rarer species. However …Cactus smuggling still happens ….money talks and corruption is rife in Central and South America.
PROPERTIES AND USES of succulent plants…………
Many of the astonishing Cactus and Succulents have a hidden value. For thousand of years they have been used as a source of FOOD + DRINK, MEDICINE, TOOLS, MATERIALS and IMPLEMENTS…..
FOOD + DRINK made from succulent plants.
Mouth watering fruits of the Prickly-Pear are eaten (Opunita ficus-indica)
Jams are made from the fruits of echinocereus Cacti
In Bolivia Neowerdermannia Cacti are used as a substitute for potato, and in Mexico the youg flat pads of opuntias are peeled, cut up and made into nopalitos. In Africa succulent tubers are eaten by the Bushmen Tribes, and Ferocacti are cut up and mixed with sugar for candied sweets.
The best known product has to be Tequila –a distilled liquor made from the boiled and fermented hearts of the agave. Locals make a lesser quality agave drink called pulque, made from the sap.
COSMETICS AND MEDICINES made from succulent plants…
The healing properties of Aloe have been known to the Greeks and Romans who used it to treat a variety of ailments from serious injury to mild skin complaints. Internally or externally – this is a wonder drug and many health and beauty products use aloe.
The night-flowering queen of the night (Selenicereus) blooms are used to prepare medicines to aid and improve circulation
The fleshy, caudiciform Tetudinaria has been used as a source of cortisone and a contraceptive pill.
The highly sought after Lophophora Williamsii (Sacred Mushroom) was used to treat asthma and rheumatism by the Aztecs. Many cacti contain hallucinogenic and antiseptic compounds not know anywhere else on this planet. Scientists are still trying to understand to powerful properties of Mescaline – a highly complex chemical which cannot be synthesized in a laboratory.
PRODUCTS AND MATERIALS made from succulent plants…
Bolivian ‘hairy old man’ Cactus Oreocereus has fine, soft, long spines that are gathered and used like wool to stuff pillows and bedding.
In Northern Mexico the stems of a Stenocereus Cacti are crushed and thrown into rivers to release toxic sap which stupefies fish so they can be scooped up by hand.
The poisonous sap of some South African Euphorbia’s is applied to arrow tips for hunting.
For Centuries Agave Sisalana has been grown to make rope, twine, sacking and matting. Even today, forests in Kenya and Madagascar have been cleared to make way for commercial plantations.
As far back as the 14th century Opuntia Coccenillifera was grown as a host plant for the coccineal beatle which was crushed to produce a rich dye- purple (female) or scarlet (male). Often used for colouring ceremonial and royal robes, the dye is still used today as food colouring and lipsticks , as an organic alternative to synthetic dyes.
IMPLEMENTS AND CONSTUCTION made from succulent plants…
Cactus spines are used as toothpicks, to make combs, gramophone needles, sewing needles and fish hooks.
Mexican succulent Calibanus has rough leaves which contain a substance similar to soap. Used for cleaning(scouring pans) and thatching roofs.
In treeless areas of South America tall growing Cereus Cacti are used for fencing boundaries and containing livestock, used to build houses and for firewood. When dried these stems are still surprisingly strong.
Opuntias are plentiful and are gathered for burning when needed. The flowering succulent Euphorbia Millii – crown of thorns, is used for its ornamental and functional benefits.
ORNAMENTAL USES of succulent plants…
The decorative appeal of cacti lies in their strange forms. Bearing little resemblance to normal ‘leafy’ plants, they range, in shape from tiny globes sometimes obscured by a flower, to creeping stems, to squat round barrels, to huge branching candelabra shapes.
They have a sculptural, almost abstract quality often highlighted by spines with the body sometimes fluted with deeply indented or studded ribs..
Succulents display a great diversity of exotic forms – from simple cac tus-like plants to more complex tree-like species. Some show the perfect symmetry of a rosette, others have loose arching or trailing stems and leaves. There are some bizarrely shaped caudiciform, bulbous and tubular plants, but you won’t see these in your average garden store.
Cacti and Succulents are some of the rarest plants in the world, and prices often reflect this.
With so many variations in stem and leaf shapes – from serrated, twisted, angular, long, slender, round, fat, heart-shaped or just plain weird shaped , one can understand the difficulty of precisely describing what a succulent plant is.
Enjoying the beauty of individual plants with unique qualities makes collecting these wonders so special. When a cactus flowers for the first time it can be breathtaking and rewarding. Pollinating flowers to produce seeds can lead to an obsession when trays of little jelly-blobs grow into mature flowering plants after years of care.
HOW TO CARE FOR A ‘SUCCULENT’ PLANT…….
TEMPERATURE, WATER , AIR,
GROWING MEDIUM , POTTING-ON / PLANTING in the open-ground,
FEEDing succulent plants and the correct PH
PROBLEMS – PESTs AND DISEASEs
PROPAGATION of most of these plants is by SEED, CUTTING, DIVISION, or GRAFTING……(time!!!)
a talk by DRYSCAPES JAY , 2008