Understanding the Two Groups of Cacti

Baja California Desert in the Cataviña region, south of Ensenada, Mexico. Cardon cactus. Date May 2003 Source Own work Author Tomas Castelazo

Growing cacti can be a lot of fun and do not require tremendous effort. Creating a growing environment may require some trial and error, but a basic understanding about these plants will pave the way.

Soil mixture, light exposure, and water are the areas you truly need to understand.

Many people knows that cacti are thorny plants that came from the desert, but what else can I add to that. I would love to share you some very basic information about cacti to help you better take care of your plants.

All cacti are succulents but not all succulents are cacti***. They are generally leafless, their stems are modified in cylinder pads, or joints that stores water in times of drought. Cacti has thick skin that reduces evaporation. Most species have spines that are actually their modified leaves that arises from an areoles. Areoles are specialized area from which the spines, wool or flowers rise; it is the cell nucleus of the plant. *Areoles are the defining part of cacti.
Cacti flowers and fruits are quite spectacular and very complex and often times are edible.

All cacti are native to the Americas and surrounding islands, from Canada to Argentina; from sea level to the mountain; from the desert to the dripping tropical forest with THE EXCEPTION OF RHIPSALIS BACCIFERA.

There are 2 groups of cacti:

1. Jungle cacti.

They include Acanthocereus, disocactus, epiphyllum, hatiora, hylocereus, rhipsalis, schlumbergera, selenicereus, and may be a few others. Their natural habitat is the rain forest. Jungle cacti are all true cacti despite the lack of big spines and inability to withstand the harsh condition of the desert.
Most jungle cacti are epiphytic or lithophytic meaning they grow from trees or grow on rocks respectively. They gather nutrients from decaying matters collected from crotches, cracks, crevasses. There are no parasitic cacti. They grow on trees for support.

Epiphyllum hookeri.   Author: i_am_jim (Own work) width=

SOIL MIXTURE for jungle cacti are rich soil composition mimmicking where they grow in their natural habitat. A soil mixture of orchid bark, perlite and oakleaf moulds, the most important part of the mixture is the drainage from perlite keeping the soil loose and airy. LIGHT EXPOSURE of jungle cacti are limited to bright indirect sunlight.

2. Desert cacti.

These are the cacti from the arid regions of the Americas. They have adapted themselves to to arid and semi-arid conditions by modifying parts or all their structure or embodiment to retain water.

Baja California Desert in the Cataviña region, south of Ensenada, Mexico. Cardon cactus.  Author:	Tomas Castelazo(Own work)

Cactus have adapted well to climatic changes that occured over a long period of time. The reduction of leaves to spines is a good example to adaptation. The lost of stem and the formation of thickened globular or columnar shapes ensured moisture loss is kept to minimum. The decline in water loss because of reduced transpiration, combined with the ability to store water in the modified tissues of the thickened body and roots, allow cacti to survive arid conditions. Desert cacti demand a fast draining soil. In their natural habitat, they grow on slopes of stones, rocks, sand with very little organic materials. Desert cacti can handle the rain but cannot stand WET FEET. Always allow to soil to dry in between watering.

*areoles, only cacti has areoles. Euphorbia mimmicks cacti and has spines but areoles are absent

***All cacti are succulents with the exception of one genus, Pereskia.

Pereskia, is a genus of 17 tropical species and varieties of cacti that do not look much like other types of cacti, having substantial leaves and thin stems. They originate from the region between Brazil and Mexico.

Thelma S. Cruz
Facebook: Cacti and succulents educational group.