by Peter Lapshin
|CULTIVAR / КУЛЬТИВАР|
e-Magazine about exotic forms of Cactaceae
ENGLISH / RUS-(Win1251)
Appearance of cacti
Any book on the cacti begin to explain what is actually "cactus." This is due to a widespread misconception about those belonging to the cactus and other plants.
With other decorative plants easier: Gladiolus-they have Gladiolus, and Sainpaulia with nothing more than confused. A variety of cacti is so great that it is very difficult to name common to them and distinct from other plant traits. At least a variety of other groups of plants live in roughly the same as the cacti, conditions, and therefore in many ways similar to cacti. Because of this dual-diversity is often taken for cacti plants, no they do not have a relationship. And on the other hand, often the real cacti cactus do not recognize.
Understand this confusion and give a strict notion of "cactus" will have to, because, not knowing what plant you have it, we can not provide him with proper care (a collection of collections, and to say no). And here, you need a certain "scientific".
Well, actually cacti - this is a plant belonging to the same botanical family (the same as the well-known family of pulses or composite). This commonality requires that all cacti certain traits inherited from their common ancestor. This is something that relates taxonomic affiliation cacti, their place in the general system of flora. In addition, they relate to the biological group of Succulent Plants. Discordant with "succulents" called plants, are in some water bodies developed parenchyma (simply put, store the water layer of cells). Depending on what parts of the plants are developing these cells, succulents fall into root, stem, leaf. It is clear that this property was necessary in the first place so plants that have mastered the arid places on Earth. As the dry steppes and deserts on Earth are many, the result of evolution in many botanical families having a wide variety of Succulent Plants. Some of them are almost exclusively Succulent plants (that is, except the Cactaceae, Crassulaceae and Aizoaceae), in other succulents make up a large or particularly prominent part of the family (Agavaceae, Asclepiadaceae, Euphorbiaceae, Asphodelaceae). In addition, many families are isolated Succulent genera and species.
Although not related to each other Succulent plants can be very similar, although they still differ on what a significant, albeit quiet grounds. For example, among the diversity of families of succulents astrovyh (Compositae), Crassulaceae and Portulacaceae are such that are easily confused with each other. But they totally unlike flowers allows to specify all of your locations. A key feature distinguishing cacti and other succulents, is a peculiar only to them areola - modified kidney. Usually areoly like small pads (often less than one millimeter in diameter) are regularly arranged on the stem plants. More about them will be discussed in the next chapter.
It is interesting that different groups Succulent plants have emerged in different places of the earth. For example, cacti are typical only for the Americas and in other parts of the world they are found only there, where they brought people. "Real Americans" are and Agave. In the drylands of Africa habitat Euphorbia, Aloe, Stapelia, Lithops and their congener. Europe and Asia - the birthplace of many Sedums.
Chapter II. Appearance cacti
Actually what we commonly call a cactus - it is the stem (sometimes incorrectly called the "body", apparently similar to the fruit body blewits-something elusively common among cactus and mushrooms actually have one). Stem of the cactus is the most diverse forms. In nature, the eyes stay in first place in the cactus tree. Some of them did not differ from the normal trees - such as a tree trunk, thick branches with green leaves, falling under adverse conditions. A tree is prickly pear cactus and the trunk and branches, but instead leaves - extended, thin, flattened shoots.
Finally, the so-called prominent pillar cacti can reach many meters high. Some of them with no branches - the tree-pillar, while others form dense interlocking branches, but the absence of leaves immediately allocates them among other trees.
In many there are cacti, bushes. Their short central stem emits a large number of lateral shoots. They can grow from the base of the stalk, and throughout its length. Such plants to look quite different.
Is not uncommon among the cacti and species with prostrate stems. The branches of such plants as the droop to the ground, take root and give the new shoots. They are a kind of "spreading" (as breeding strawberry mustache), covering entirely suitable for this place.
There are curly and cacti, there are even such liana. They can grow both on the ground and epiphytic (on other plants), on rocks, etc., and extending for several meters, the stalks form a thick binding.
Many interesting and diverse purely epiphytic species partially lost Succulent, the runners are not as meaty as the stalks remaining cacti. They are usually thick beams hang from the other plants.
In culture the most popular plants with round or short cylindrical stems. Few of them all his life remained single stalk. Most, especially in the later age, gives the side branch at the base. Side shoots can be so many that they form a "cap" the shoots, the lower of which gives the roots and, in turn, are beginning to branch. So a whole colony. In nature, these colonies can grow wide as the blanket covering the earth.
Some cacti are part of the underground stem. Some - in the form of roots or stolons, contributing to growing plants. Other underground stem contributes to feelings of adverse conditions.
Most cacti - plants with a continuous growth with a growth zone in the top of the stalk remains all his life, and increase each year, virtually indistinguishable from plots grown in previous seasons. But a lot of cacti have a finite growth - the division of stem cells in the top periodically stops, then a new escape from any areoly. To stem these plants is characterized by articulate (segmented) structure.
Surface of the stalk is not completely flat. Usually, its structure creates ribs, tubercles, or papilliferous. The ribs are straight, down steeply from the top to the base of the stalk. But can they pass at an angle relative to the axis of the stalk, and even spiral swirl past. Do Stenocactus wavy bent, which makes these plants very artsy look.
Some cactus ribs are so flat that it is almost not rise above the surface and the stalk appears almost flat. Often the edges into a series of tubercles or papilla. Papilliferous tubercles distinct from that associated with the split areoloy: papilla located on the top part areoly with a thorn, and in the sinus - part of which developed side-shoots and buds. Protuberance is associated with an entire, undivided areoloy, located either on top or in the sinus tubercles. The division is largely notional. And papilliferous, and tubercles are a variety of shapes and sizes.
Some species of cactus leaves persist. They can be as "normal" - with a solid oval leaf plate, constantly on the plant, and modified: cylindrical, ephemeral, existing only on the young sprouts. There are also rudimentary and leaves, barely visible in the zone of growth.
Characteristic feature of cacti - the existence areol (modified axillary buds). Outwardly areoly - this round spots of different diameters. They have thorns, pubescence; areol of the majority of cacti appear, young shoots and buds.
Thorns cactus - modified leaves axillary escape. The variety of their unusual - subulate, bristles prominent, hair visible cirrus, paper pieces, iglo prominent, whimsically crooked, hooks prominent converted to glandule, of varying sizes and of various colors. Number of thorns, associated with one areoloy may vary from one to many tens.
The representatives of subfamily Opuntiaideae in areoly sure there are peculiar tiny jagged thorns - glohidiya. When they are very much, because they have bright coloration and tiny size make areole chic look. But do not tronte this beauty! It is an obligation glohidii cacti standing awfully prickly plant. Most cacti, despite the luxurious prickles, little prick.
It is the above-mentioned education, which can be seen in some cacti areolah - gland. They provide ... syrup - a thick solution of sugar. Spreads on the stalk sugar creates some problems in the cultivation of cacti (but more on that - below).
Of areoly same flowers appear and the cactus. Their diversity is so great that the general characteristics required of a few words, but the options will be discussed below.
Cactus flower mostly singles. Mention of the "heads" - an error, not a cactus and flower stalks, flowers emerge directly from the stalk. But several groups are formed on the stem or the special zones - cephaly, where flowers are formed. Zones of flowering and cephaly may appear dramatically different from the rest of the stem of the cactus form, color, pubescence, thorns.
A primitive cactus flowers perianth leaves have no division in the petals and sepal, their quantity, as the number and percentage of tychinok pistil stigma, not fixed.
Sizes of flowers ranging from a few millimeters to 40 cm Their symmetry can be radial or zigomorfnoy (bilaterally symmetric).
Shape of flowers is also very different - from wide to narrow pull-down tube, in which only the edges turn up most of domestic leaf perianth. There are cacti with night and day with flowers. Some flowers amaze whimsical, exquisite flavor, and is - entirely deprived of smell. And their color can be seen any other than the blue and black.
No less diverse fruits of cacti - from large juicy berries until a small box with dry seeds.
Invisible part - the roots - often represented by a prominent broom root system. But some kinds of size and weight of massive thick roots can be several times greater than the size and weight of aboveground parts of plants.
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