Cactaceae

Cactus is the usual name of the plants of the family of the Cactaceae , order of the Caryophyllales . They are also called cactées . They all are almost of the fatty plants or succulent plants, i.e. Plante S Xérophyte S which store in their fabrics of the reserves of “juice” to face the long periods of Sécheresse.

However one should not confuse cactus and succulent Plante: all the succulent plants are not cacti because other families of plants adopted this method of fight against the periods of dryness, like the Asclepiadaceae or the Crassulaceae . Certain plants of these other families, by convergence of the forms of species subjected to the same constraints, strongly resemble the cacti. It is the cactaceous case for example Euphorbe S like Euphorbia canariensis . To distinguish truths cactus from the plants which resemble to them, it is necessary to refer to the criteria of membership for the family of the Cactaceae .

Classification

The family of the Cactaceae or cactus is a family of plants Dicotylédone S which includes/understands approximately 2000 species divided into nearly 90 kinds. They are herbaceous plants or Arbuste S, generally with very particular vegetative form, with the chlorophyllian function transferred to the Tige S. Souvent thorny, perennial, generally succulent, the cactus are sometimes épiphyte S or climbing.

The Cactaceae are present naturally areas moderated at tropical, mainly on the American continent. Their particular morphology in fact of the required plants of ornament and the cactus are the object of the care of many amateurs. The fruits of certain species are edible (Prickly peartree).

Cactus was also a name of kind in the binomial Classification codified by Carl von Linné. It appears more in current classification only like suffix of certain names of kind, such as Echinocactus , Pterocactus , Stenocactus , etc In the language running, the word cactus often indicates the Prickly peartree ( Opuntia ficus-indica ), very common plant naturalized on the edges of the the Mediterranean.

Criteria of determination

The membership of the family of the Cactaceae is determined by three principal criteria:
  • the ovary must be infère, i.e. it must be located under the floral parts (except at some very primitive cacti like Pereskia aculeata ).
  • the Fruit must be a bay with only one cabin, there do not exist internal partitions separating the Graine S or groups from seeds.
  • the vegetative points are areolas, i.e. kinds of depressions in the skin, furnished with wool or sleeping bag giving them the aspect of small cushions, from where the segments or rejections result, the Fleur S and the transformed Feuille S that are the spine S, the Soie S, the Glochide S… The existence of areolas is the criterion more employed by the amateur, initially because it is not necessary to await flowering and fructification to observe them, then because, contrary to the two other criteria, the areolas do not exist in any other family of plants.

Morphology

The current aspect of the cactus is explained mainly by the adaptation to the conditions of Sécheresse, at the origin of the development of the function of storage and the reduction of surfaces of evaporation.

The function of storage resulted in a thickening of the stem, and, for some species, by the development of roots tuberoses ( Pterocactus tuberosus for example). She explains also the appearance of the coasts or a provision of the nipples in spiral, which allow, a little as on a Accordéon, the dilation and the retraction of the body of the plant to the liking of the periods of Pluie S and Sécheresse, without tear of the skin.

The reduction of surfaces of evaporation resulted in a thickening of the skin, sometimes even covered with a kind of wax, a reduction in the number of Stomate S (Pore S allowing breathing), and especially, at much of species, the disappearance of the sheets (see evapotranspiration).

As for the spine S, their function is multiple: protection against the animal , but also collecting of the Dew, protection of the skin against the heats of the Sun, the Wind dessicant or the Cold of altitude…

The cacti can be gathered in five great morphological types:

  • primitive Cacti - Not or not very succulent, these cacti kept the aspect of traditional Arbuste S and their true Feuille S: Pereskia , Pereskiopsis , Quiabentia .

  • Opuntia S - Made of thick segments in the shape of rackets ( Opuntia ), sometimes at the top of a trunk ( Brasilopuntia , Consolea …), of segments in the shape of cylinders ( Austrocylindropuntia , Cylindropuntia , Grusonia …) or of small more or less lengthened balls ( Maihueniopsis , Tephrocactus …), these cacti, for the majority, preserved reduced and cylindrical sheets, falling quickly.

  • column-like Cacti - Made of Stem S thick and lengthened, drawn up with crawling or falling down, their areolas is laid out along coasts ( Escontria …).

  • globulous Cactus - They are made of spherical stems being able to lengthen, with the areolas laid out on coasts ( Astrophytum …) or on nipples in spiral ( Mammillaria …). At the most evolved/moved, the areola divided, that located at the axile of the nipple producing Fleur S and rejections, that at the top of the nipple producing the spine S. Of the intermediate forms of this phenomenon, called Déhiscence serial, present a furrow connecting the two parts of the areola in the course of division.

  • Cactus épiphytes with flattened stems - These cacti pushing in wetter zones reduced their storage capacity and their flattened stems resemble the Feuille S which they replace in their chlorophyllian function ( Schlumbergera , cactus-orchises…)

Some kinds

The Echinofossulocactus from now on are classified among the Stenocactus .

Culture of the cacti

Watering

Contrary to an generally accepted idea, the cactus need Eau to push and flower. They can however occur some for very long periods.

Watering must be regular and abundant: all the Ground must be wet. To avoid the Rot, water must be able to run out quickly without remaining with the foot of the pot (not cup), in order to let well dry the Ground between two waterings.

The cacti can profit from manure once a month, and maximum a watering on three. Proportion NPK of manure with géranium is appropriate for the majority of the cacti. During the winter rest, waterings must be rarer.

Flowering

Flowering, often spectacular, is short (to the maximum 8 days). Some variety S flower during the night (night varieties), like the Selenicereus , called Queen-of-the-Night , and others the day (diurnal varieties). The diurnal species are most generous and the flowers are silkier.

Half of the species only flower at the time of their first years, in condition only of spending the winter in a fresh and luminous place, and with the dry mode with very little water (1 time per month). This treatment makes it possible to roughly reproduce the conditions of the dry season in the Désert.

Certain species flower easily, but of others requires particular care and are able to provide flowers only after four or five years of growth.

Winter rest

The winter rest consists in leaving the cold cacti and to dryness during the winter. It is preferable to stop waterings between September and April or November and March, according to the local Climat.

The temperature to be respected must vary between 5 and 10 degrees Celsius if the ground is quite dry. Freezing should be avoided, although certain species of cactus pertaining to the kinds Opuntia , Escobaria or Echinocereus can resist up to -20 °C! For other species, like the Melocactus , it is necessary to avoid going down in lower parts of 10 °C.

Luminosity

The luminosity is a crucial factor. Many cacti come from the Mexico, a very sunny country. Even if some push in the shade of grasses or the shrubs, they receive more light than if they were in full sun in France! In France, it is preferable not to put them in full sun (the difference between the sun of winter and the sun in summer is too large, and that the plants “will burn” with the first sun rays). If the plants do not have enough light, they go étioler; they will be green pale. The light is a dominating factor for the formation of beautiful pivots.

Substrate and pots

The majority of the cacti live in grounds very low in organic matters. A mixture of culture which can be used is ground-compost-sand (1/3 of each). Sand must be 2 to 5 mm and the well broken up compost. It is also possible to use the pearlite or pozzolana. It can be interesting to sterilize the compost before use (with the micro wave for example).

The pots used can be in Terra cotta or plastic. Let us quote some selection criteria:

  • Esthetic: in general, ground pot.
  • Evaporation: the ground dries more quickly with the ground pots because they are porous.
  • Weight: the plastic pots are much lighter (favors for transport) but the ground pots are more stable (cactus of big size).
  • Cost: the ground pots are most expensive.
  • Repotting: it happens that the roots adhere to the ground pots.

The plants must be repotted for two reasons:

  • Growth: the plant growing, its roots need more than space.
  • Degradation of the ground (out of pot), which must be renewed.

Repotting is the occasion to observe the plants for the presence of parasites, the appearance of rejections, general health…

The rules of repotting to be respected are to remove the maximum of old ground and not to damage the roots. The pot can be changed or not. It is possible to add sand or stones to the bottom it pot to facilitate the drainage. It is possible to add in last layer of sand or the fine gravels to prevent that moisture does not stick to the collet of the plant and to avoid digging the ground during watering. It is also preferable to wait one or two weeks before starting again watering (time until the wounded roots heal). The frequency of repottings is variable: every year in the event of strong growth, every 2/3 years for the old plants. Repotting is generally practiced after the winter rest, in spring. An alternative method of repotting, which lets at the same time create, inside the vase, a consistent water tank, sufficient at least for thirty days, contemplates the use of a device sealed in permeable material (woven not woven), which contains inside right very necessary for the maintenance and the drainage of the decorative plants. Pose the device in water, to wait 40 minutes, to give temp to the crystals of freezing superabsorbent contained inside increasing completely (they absorb up to 450 times their weight in water), insert in a pot with an adapted diameter, adding the seedling and supplement repotting as usual. Manure with slow emission, contained inside the device, ensures the good quantity of food substances for all the season of growth. According to the indications provided by manufacturing it, the device (called " Florero®") is able besides to ensure the correct drainage of the ground, avoiding the putrefaction of the radical apparatus.

Multiplication

There exist two methods of propagation of the cacti and other succulent plants: the Propagation by cutting and the Sowing. It is also possible to be helped of the Clerc's Office, but it is not a method of multiplication itself.

The propagation by cutting functions particularly well with the cacti which reject ( mammillaria , rebutia …), because one can cut a rejection of it. For the cacti in articles ( opuntia , tephrocactus …), it is enough to cut one of them. For the succulent ones, that depends on their type. With the species with succulent sheets ( adromischus …), it is enough to detach a sheet. With the species with succulent stems ( aeonium …), it is necessary to cut one of the stems. That wants to thus say that all the plants cannot be multiplied vegetatively (for example: astrophytum species, euphorbia obesa , certain candles, etc). If you want absolutely to multiply these plants in a vegetative way, they should be decapitated, to induce the production of rejections (attention, decapitation is a risky method because it can lead to pure and simple death plant).

The plant with bouturer must be in full growth. You must provide yourselves with a clean knife and sharpened well to take your cuttings. Then, they must dry more or less a long time, according to their size. For a cutting of the size of an olive, count one week in a fresh and aired place, with the shelter of the sun. For a cutting of the size of a tangerine or larger, one needs that one cal is formed, that can take until several months. In the doubt, wait longer.

Once your cutting is dry, you must pose it on a rather mineral substrate. Mix for example your usual mixture with an equal quantity of coarse sand. Watering must be parsimonious, until the appearance of the first roots.

For sowing, it is necessary to get seeds, fresh if possible. You can take them on your own plants, or the acheter.
The best time to sow is spring. If you want to sow at another time of the year, a propagator (small heating greenhouse) is necessary. The substrate must be very mineral (sand).

The seeds must be distributed most uniformly possible on the substrate, then covered with a layer of sand thickness equalizes with them. The whole must then be kept completely wet until the appearance of the first seedlings. A manner easy to do that consists in locking up the pots in plastic bags. When the first plants appear, it is necessary well to air, and make it possible the substrate to dry a little. Then, the proportioning of watering must prevent the seedlings from being desiccated, without they rotting. It is possible to add a fungicide to the water of watering, in order to prevent the cast iron of sowing.

The seedlings can be repotted as of next spring. Sowing makes it possible to have plants from 1 to 3 cm in diameter in 18 months, for the majority of the species.

Parasites

The most frequent parasite is the white Cochenille, located on the air parts of the plants. Certain plants are very vulnerable, others seem immunes. Also attends, the cochineal of the roots which parasitizes the plants on the level of the roots and the Red spider.

Manure

The cacti can live or survive with very little nutritive matter. But for beautiful vigorous plants, a contribution of manure can help. Frequently advised report/ratio NPK is of the 1:2 type: 3 or 1:2: 4, in the form of liquid manure or of Manure to slow diffusion.

Use

The uses of the cacti, apart from decoration, are rather astonishing. Certain people were refreshed for example water contained in the Cereus . The Opuntia ficus-indica , more commonly called Prickly peartree, produced edible fruits.

If that were not shown scientifically, the cactus would have for some the astonishing capacity to absorb the harmful waves diffused by the high electromagnetic sources like low frequencies. What says research on this subject? Nothing. It is non-existent, if not the work of hypnotizers, geobiologists or other esoterists naturopathes, whose pseudoscientific declarations cannot be confirmed by true studies with the irreproachable protocol.

See too

  • Guy Xhonneux
  • Organ Pipe National Cactus Monument
  • National Saguaro Park

Sources

  • With the French-speaking Cactus
  • '' Cactus and Succulent Seedling Badly ''
  • Kuentz, the World of the cacti (commercial site)
  • the Colombian '' Cactaceae ''
  • Specialized site in '' Cactaceae '' épiphytes

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