Cacti are Native to the Americas and off shore islands. They can be found up to 4000 metres altitude from Hudson's Bay to Terra Del Fuego. They grow just about anywhere you can imagine.
There are about 3000 species overall, but botanists keep changing their minds. Many named species are now considered to be only varieties (v.) or forms (fa.) of others. There are about 120 Genera, and countless forms and other varieties. They are a major plant group. All cacti are succulents but not all succulents are cacti.
- Angiosperms, = having seeds in a closed ovary;
- Centrospermeae = seeds in the centre of the fruit;
have one celled fruit;
- Are perennial = they live for years,
- Dicotyledons = have two seed leaves;
- Have ovary below the petals;
- Flower each year and often, and have many stamens;
- Contain a nitrogenous dye, Betalaine;
- Have ribs with raised lumps = Tubercules often arranged
- Have spine cushions = aereoles from which spines or
wool or both grow (spines etc. are not permanently
attached and are not part of the flesh similar to bark on
The tissue contains a woody heart, a cambium = growth
layer, sap tissue and often a cork like bark. The cambium allows any cactus to be grafted onto any other.
All have magnificent flowers. Some live for centuries, some a year or ten or anywhere in between. Most like total drainage. A good soak between dry outs and minimum slow release fertilizer in an acid pH mix of sands and fine gravel with say 20% coconut fibre = "coco-peat" is the best medium to grow them in. Sun is essential, but some like light shade.