For succulent perennial vegetable organisms we mean plants that are equipped with aquifer parenchyma, spongy tissues that serve to retain even considerable amounts of liquids so to speak of reserve. If it is true that nature never ceases to amaze us, it must be said that one is fascinated by the reality of a vegetable that over time has been able to evolve and refine itself in order to make the most of the water received from the rain, and then exploit it during months of drought, channeling it to every part of the body that needs it. And it is precisely the permanence of the water that gives each individual part the typical swelling that makes fleshy stems, leaves and even the Cactus roots that, remember, is a perennial plant. Cactaceae are called xerophytic plants, which means that they develop in arid areas or better managed to survive in arid areas thanks to their brilliant ability to adapt to really difficult climatic conditions. They are part of the scientific order of the Caryophyllales, class Magnoliopsida, division Magnoliophyta, superdivisione Spermatophyta.
The water received is placed in the various aquifer parenchymes we have mentioned, present in various parts of the plant, that is in some spongy tissues composed of roundish cells of considerable size with intercellular spaces to be filled, where the liquid that will be put back into circulation is precisely preserved. in periods of lack of water. To ensure even more effective conservation, the Cactus plant produces protective waxes and also produces trichomes (a kind of hairs placed on the external surfaces) that have the function of limiting the dispersion of the water present in the plant body to the maximum by transpiration.
Even the absence of leaves or in any case their presence only to a limited extent and the particularly squat and compact structure of the Cacti complies with the need to retain liquids, as if the plant were trying to resemble as much as possible to a sort of very original barrel . The mechanism of photosynthesis takes place in the stem of the plant.
How this plant is used
Despite the apparently rustic appearance, the Cactus is lately very appreciated as an ornamental plant, perhaps because of the particularity of its structure, but the Caryophyllales family it belongs to is very rich and varied and in fact also includes beets, spinach and rhubarb which are instead classifiable as crop plants.
This is to explain that the Cactaceae are more complex than is mistakenly believed.
Cactus fruits can be eaten, just think of the prickly pear, widespread also in Italy because it is widely cultivated in the southern regions.
A plant with many faces
There are Cactus with very different shapes and sizes. In nature it is even reported the existence of a Cactus that reaches more than unusual height of almost 20 meters: it is called Pachycereus pringlei, but there are also versions that we would call spontaneous bonsai: the Blossfeldia liliputana species has only 1 cm of diameter at most of its development.
The name Cactus comes from the Greek word kаktos, which means thistle. The name was attributed to these plants by Carl Nilsson Linnaeus, a Swedish physician and naturalist, in the year 1753.
The flowers produced by the cacti are quite large and are born from the areolas, just as it happens for thorns and branches. It should be added that many species have a particular feature: they bloom at night because their pollination occurs due to the activity of insects that act during the night, but also due to the movement of animals such as bats. The Cactus flowers are bisexual: they have an inferior ovary and many stamens.
The subfamilies of the Cactaceae. The life cycle
The family has four subfamilies, namely the Pereskioideae, the Cactoideae, the Maihuenioideae, the Opuntioideae. These plants develop during the summer months and enter the classic vegetative phase during the winter. Some species have developed the ability to survive even at temperatures below 15 degrees and this is also one of the secrets of their growing diffusion.
Cactus plants: What to do in case of diseases
The catus can be affected by fungal or bacterial infection and in these cases it is necessary to intervene quickly to avoid the death of the plant. We must use a well disinfected knife, but also very sharp, and proceed to cut the portion that shows a characteristic dark color and the beginning of the formation of a real cavity. The area that remains uncovered, which must not have dark spots, must be treated with a fungicide to prevent the formation of a new infection.