Pomelo is very large citrus fruit of botanical name Citrus maxima. It is very sweet taste after ripening . Have you ever tried a honey pomelo ? This large citrus fruit can be found in the produce section from late fall to early spring. Here's more about this tasty unique citrus fruit.The fruit is used in many festive celebrations throughout Southeast Asia. After a Captain Shaddock of an East India Company ship introduced it to Barbados, the fruit was called "shaddock" in English. The fruit is also known as jabong in Hawaii and jambola in varieties of English spoken in South Asia. The etymology of the word "pomelo" is uncertain. It may be an alteration of "pompelmoes", in Tamil pomelo are called pampa limasu, which means "big citrus". The name was adopted by the Portuguese as pomposos limoes and then by the Dutch as pompelmoes. Typically, the fruit is pale green to yellow when ripe, with sweet white ( or, more rarely , pink or red) fle...
Morphology
Ferrocactus species, a cactoid, in its native Arizona habitat
1,500 to 1,800 species of cacti mostly fall into one of two groups of "core cacti": Opuniatus (subfamily Opuntioidea) and "Cactoids" (subfamily cactoids). Most members of these two groups are easily recognizable as cacti. They have fleshy juicy stems which are the major part of photosynthesis. They have absent, small or ephemeral leaves. They have flowers with ovaries that lie beneath the petals and petals, often deeply submerged in a fleshy receptacle (the part of the stem from which the flower parts grow). All cacti have isolates - highly specialized miniature shoots with extremely small intodes that produce vertebrates, normal shoots, and flowers.
The remaining cacti only fall into two genera, Parascia and Mahuenia, and differ, which means that complete descriptions of cacti must often be an exception to them. The Parascia species superficially resembles other tropical forest trees. When mature, they have wooden stems that can be covered with bark and long-lasting leaves that provide the main means of photosynthesis. Their flowers may have superior ovaries (ie, above the point of attachment of sepals and petals), and areoles that produce further leaves. The two species of Mahuenia have short, globe-shaped bodies with prominent leaves at the top.
Habit of development
Cacti show a variety of growth habits, which are difficult to divide into clear, simple categories.
Arsantes cacti
They can be tree-like (splendid), which means that they usually have one or more-less woody trunks that are several to many branches. In the genus Periscia, the branches are covered with leaves, so species of this gene cannot be recognized as cacti. In most other cacti, the branches are usually cactus-like, bare of leaves and bark, and covered with spines, as in Pachyceres pringlei or large opunities. Some cacti may be tree-shaped, but without branches, such as large specimens of Echinocactus platacanthus. Cacti can also be described as a shrink, with many stems coming down from the ground or very far from the branches, as in Stenoceras thurberry.
Columnist cacti
Small cacti can be described as pillars. They include columns, cylinder-shaped stems, which cannot or do not branch, without a very clear division into the trunk and branches. The boundary between column forms and tree-like or shrub forms is difficult to define. For example, the smaller and smaller specimens of Cephalocares cenilis have columns, while the older and larger specimens may become tree-like. In some cases, the "column" may be horizontal rather than vertical. Thus, Stenoceras eruca consists of stems that grow along the ground, at intervals.
Globular cacti
Cacti whose stems are even shorter can be described as spherical (or globose). They consist of a smaller, more ball-shaped stem than the columnar cacti. Globular cacti may be acute, such as Ferocactus laticinus, or their trunks may form flakes that can form large mounds. All or some stems in a cluster may share a common root.
other forms
Other cacti have a very different appearance. In the tropics, some forests grow as climbers and epiphytes. Their stems are usually flat, almost leaf-like in appearance, with little or no spine. Climbing cacti can be very large; One specimen of Hilleocares was reported to be 100 m (330 ft) long from the root to the farthest stem. Species of epiphytic cacti, such as Rhipipalis or Shalamborara, often hang downwards, forming dense clumps, where they grow in trees above ground.
Stem
The leafless, glabrous stem is characteristic of most of the cacti (and all belonging to the largest subfamily, the cactoid). The stem is usually succulent, meaning that it is adapted to store water. The surface of the stem may be smooth (as in some species of Opuntia) or covered with a variety of protuberances, commonly called tubercles. These vary from small "bumps" to various types of nipple-shaped mammillariae and outbreaks almost like leaves in the genus Eriocarpus. The stem can also be rib shaped. The prominence of these ribs depends on how much water the stem is storing: when full (water can be up to 90% of the cactus's mass), the ribs can become almost invisible on the inflamed stem, while the cactus When water and stems shrink, ribs are very visible.
Most cacti stems are green, often green or brown. Such stems contain chlorophyll and are capable of photosynthesis; They also have stomata (small structures that can open and close to allow passage of gases). Cactus stems are often waxy in appearance.
Areoles
Areoles are structures unique to cacti. Although variable, they usually appear as stems or hairy areas from which the spine emerges. Flowers are also produced from areoles. In the genus Periscia, considered to be similar to the ancestor of all cacti, the leaves are in the axils (i.e., the angle between the leaf stalk and the stem). In leafless cacti, stitches are often borne on raised areas where the leaf bases were.
Arrows are highly specialized and very concentric shoots or branches. In a normal shoot, nodes containing leaves or flowers will be separated by the length of the stem (internodes). In a pole, the nodes are so close together, they form a structure. It may be spherical, elongated in oval shape, or even separated into two parts; The two parts may be connected in some way (such as by a groove in the stem) or appear completely separate (a dimorphic isolate). The top part of the stem then produces flowers, the other part rotates. Aryol often has multicellular hairs (trichomes) that give the areola a hairy or woolly appearance, sometimes of a different color such as yellow or brown.
In most cacti, areoles produce new spines or flowers for only a few years, and then become dormant. This results in a relatively high number of spinal cords, producing flowers only from the ends of the stems, which are still growing and forming new areoles. In Periscia, a genus close to the ancestor of Cacti, areoles remain active for a very long time; Opuntia and Neorimondia have the same situation.
Leaves
The great majority of cacti have no visible leaves; Photosynthesis occurs in stems (which may flatten and leak in some species). Exceptions occur in three groups of cacti. All species of Parascia are superficial like normal trees or shrubs and have many leaves. Many of the cacti (subfamily opuntioides, opuntioides) in the Opuntia group also have visible leaves, which can be long-lasting (as in the Peresopopis species) or arise only during the growing season and are then lost. (As in many species of Opuntia). The small gene mahuania also relies on leaves for photosynthesis. The composition of the leaves varies somewhat between these groups. There are "normal" leaves of the genus Periscia, with a midbrit and a flat blade (lamina) on either side. Opuntioids and Maihuenia have leaves that appear to consist of only one mibriar.
Even without visible photosynthetic leaves, cacti usually have very small leaves, which are less than 0.5 mm (0.02 in) and almost always less than 1.5 mm (0.06 in) in about half of the species studied. it happens. The function of such leaves cannot perform photosynthesis; A role in the production of plant hormones, such as auxin, and in defining axillary buds has been suggested.
Fork
Botanically, "thorns" are distinguished from "thorns": the spine is modified leaves, and the thorns are modified branches. The cacti produce the spine, always as stated above. Spines are also present in those cacti with leaves such as periscia, periscapsis and mahuania, so they develop markedly before becoming completely leafless. Some cacti are only young when presumably planted only. This is particularly true of tree-living cacti, such as Rhipipalis and Shalamborara, but some ground-living cacti such as Eriocarpus.
Cacti vertebrates are often useful in identification, as they vary greatly between species in number, color, shape, size, and hardness, as well as whether all the spines produced from a mole are the same or whether they differ Are of type. Most of the spines are straight or slightly curved, and are described as hair-like, bristle-like, needle-like, or convulsive, depending on their length and thickness. Some cacti have flattened spines (for example Scleroctectus paparachanthus). Other cacti have thorns. Occasionally, one or more central spines are inclined, while the outer spine is straight (eg, Mammillaria taki).
In addition to normal-length vertebrates, members of the subfamily opuntioidea have relatively short vertebrates, called glossids, which are prickly along their length and are easily shed. They penetrate the skin and are difficult to remove, causing long-lasting irritation.
Flowers
Like their spine, cactus flowers are variable. Typically, the ovary is surrounded by material originating from the stem or receptus tissue, a structure called pericarpale. The tissue emanating from the petals and petals continues the pericarpel, forming a composite tube - the whole can be called a floral tube, although strictly only the part from the base is floral in origin. Outside the tubular structure are often wools that produce wool and spine. Typically, the tube also has small scale-like cracks, which gradually transform into sepal-like and then petal-like structures, so the sepals and petals cannot be clearly differentiated (and therefore often " called "tepals"). Some cacti form flower tubes devoid of wool or spines (such as gymnoclycium) or completely devoid of any external structures (eg mammillaria). Unlike other cacti flowers, percussia flowers can grow in groups.
Cactus flowers usually have many stamens, but only one style, which can branch end in more than one stigma. The stamens usually originate on the inner surface of the inflorescence of the inflorescence tube, although in some cacti the stamens are formed in one or more distinct "chains" in more specialized areas inside the inflorescence tube.
The flower as a whole is usually radially symmetric (actinomorphic), but some species may be bilaterally symmetric (zygomorphic). The color of the flowers ranges from white to yellow and red to magenta.
Optimization for water conservation
There are some adaptations to promote efficient water use in all cacti. Most cacti-opentia and cactoids - specialize in surviving hot and dry environments (ie they are xerophytes), but the first ancestors of modern cacti were already adapted to the drought period. A small number of cactus species in the tribes have adapted to life as Himalory and Repleniselia climbers or epiphytes, often in tropical forests, where water conservation is no less important.
Leaves and spine
The absence of visible leaves is one of the most important characteristics of most cacti. Periscia (which is close to the ancestral species from which all cacti evolved) has long-lived leaves, which, however, are dense and juicy in many species. Other species of cactus with long-lasting leaves, such as opuntioid periscapsis, also have juicy leaves. An important issue in retaining water is the ratio of surface area. Water scarcity is proportional to surface area, while water content is proportional to volume. Structures with a high surface area-to-volume ratio, such as thin leaves, lose water at a greater rate than structures with necessarily lower area-to-volume ratios, such as thick stem.
Spines, which are modified leaves, are also present on cacti that are with true leaves, showing the development of the spines prior to leaf loss. Although spines have a high surface area-to-volume ratio, during maturation they contain little or no water, which is made up of fibers made of dead cells. Spine provide protection from herbivores and camouflage in some species, and in many ways aid water conservation. They trap air near the surface of the cactus, creating a moister layer that reduces evaporation and evaporation. They can provide some shade, which reduces the surface temperature of the cactus, also reducing water loss. When sufficiently moist air is present, such as during fog or early morning mist, the spine can condense moisture, which then drips onto the ground and is absorbed by the roots.
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