Prosopis pallida syn. Prosopis limensis
- American Carob
A leguminous plant, Prosopis pallida is one of the mesquite tree species. This plant is indigenous to Ecuador, Colombia and Peru, especially in the arid coastal regions. Although its existence is threatened in its place of origin, in several other places, mesquite is thought to be a very invasive species. Mesquite trees are very common in the American southwest.
Mesquite is basically a very large tree that often grows up to a height of anything between 8 meters and 20 meters, while the width of its trunk is usually about 80 cm across. It also has a very long life when grown in suitable conditions. However, the plant is reduced to the size of a shrub when grown in infertile land where there is a scarcity of water. The trunk is irregularly fuste, twisted as well as knotty. The external bark of the plant has a brown-gray-blackish color and is fissured having woody rhytidome, which often has spines. The inner bark of the tree is white and red hued. It has a bitter and varnish scented fiber-like texture.
The cup of the trees is usually horizontal and has the shape of an umbrella. It may be wide or occasionally spherical or globose. It is evergreen. While the branches of mesquite are twisted, the foliage is copious.
The fruit of mesquite is basically a pod or legume, which grows up to a length of anything between 16 inches and 30 inches and its width is a little more than 1.5 cm, while its thickness is about 8 mm. Usually, the weight of one mesquite pod is roughly 12 grams and it encloses three main segments – the external shell, the seeds and the pulp. All these are contained in a hard shell that is difficult to open. Each pod contains about 25 seeds on average. All the components or parts of the mesquite fruit are used. According to estimation, on average, one mesquite tree produces approximately 40 kg fruit every year. Generally, 70 trees grow in one hectare of field.
Usually the bark of the aged mesquite tree branches is uneven, cracked and its color may vary from grey to brown or black. On the other hand, the bark of the young branches of this tree is smooth and its color may vary from green to reddish. The tender branches generally have a crisscrossing growth pattern. At times, the young branches have sparse hairs or bristles (for example, puberulent), but they usually lose all their bristles (for instance, glabrous) as they age. The stems of this tree are equipped with two spines (measuring anything between 3 mm to 17 mm in length) and they are found just a little higher above every leaf fork (for example, the axils).
The leaves of mesquite appear in an alternate display and are twice-compound (bipinnate). The leaves have a resemblance to those of ferns. The leaves appear on very light, hairy stems (also known as puberulous petioles) and grow up to a length of 8 mm to 20 mm and generally have branchlets (pinnate), which may vary between two and four pairs. Each branchlet or pinna measures about 2 cm to 5 cm in length and produces anything between 7 pairs and 15 pairs of oblong-shaped to somewhat elongated leaflets (pinnules). The leaflets are about 2 mm to 10 mm in length and approximately 1.4 mm to 4.4 mm wide. Precisely speaking, they are usually two to four times longer compared to their width. Generally, they are rather hairy (for instance, pubescent) on both the sides and their tips are weakly pointed or curved (having either sharp or obtuse apices).
The flowers of this tree appear in clusters or racemes, which are elongated and cylindrical. Each of the racemes may be about 8 cm to 12 cm in length and appear on the stalks (peduncles) whose length may vary between 4 mm and 30 mm in length. About two to five stalks may emerge from one leaf fork or axil. The flowers are petite and they have different colors: whitish, creamy, greenish or more frequently yellowish. Each flower has five subtle sepals whose length may vary between 0.5 mm to 1.0 mm and they are joined together to form a calyx tube (a small tube). The flowers have five little petals, each measuring about 1.5 mm to 3.0 mm and they are joined at their base. The flowers also comprise 10 noticeable stamens which are about 5 mm to 6 mm in length. The trees are mainly in bloom during the summer.
The mesquite trees form a major source of nitrogen supplies to the soil, especially in dry areas. In addition, their fruits contain a variety of nutriments, including vitamin C, vitamin E, minerals (potassium) and elevated levels of sugar (sucrose), which are said to be responsible for its therapeutic as well as nutritional attributes. Despite this, trees growing in more than 10,000 hectares of forest lands are felled every year mainly for being used as charcoal! In this way, more than 50 per cent of mesquite fruits are lost, while another 15 per cent is used for feeding cattle. Only the remaining 35 per cent fruits reach the wholesalers, who market them for an assortment of uses. A part of these fruits is also used to feed animals, while only a small portion is employed to prepare mesquite syrup, which is used in drinks, cocktails and a number of sweets that are made manually.
Ecologists are of the view that the mesquite trees are vital for our ecosystem, especially in the desert regions on the western side of the Andes in south of Peru. This is mainly because this tree has the aptitude to attach moisture to the ground, thereby preventing soil erosion. All prohibitions by the local authorities notwithstanding, the poor villagers in the region still cut down these trees to use them as charcoal. Currently, there are efforts to reforest the entire area by planting large number of new mesquite trees.
The timber of mesquite trees is tough, which makes it an excellent material for making furniture as well as implements. The timber of two mesquite tree species – Prosopis glandulosa and Prosopis juliflora, is used to make ornamental wood works as well as for woodturning. These woods are in high demand owing to their dimensional stability after they are completely cured. The firm, dense logs of these trees are also marketed in the form of ‘Texas Ironwood’ and it is somewhat harsh on chain saws as well as different other tools.
When used as firewood, mesquite logs smoulder bit by bit and are extremely hot. When you use the mesquite wood for barbecue, the smoke of the burning wood helps to add a distinctive essence to the foods. This practice is quite widespread in the Texas-style as well as Southwest barbecue.
Mesquite wood is used for grilling or roasting purposes with a view to smoke-flavour chicken, fish, pork and steaks. You can also add mesquite wood smoke flavouring to other foods like soups, scrambled eggs, vegetable stir-fries and also ice cream.
The seed pods borne by mesquite trees are dried up and pulverized to make flour, also known as mesquite meal. As the mesquite trees are very common in southwest America, the tree as well as its pods formed an important staple food for the Native Americans, who pulverized the pods to make sweet tasting flour, which was used to prepare soups, porridge, puddings, dried cakes and even drinks. People also picked the dry pods directly from the trees and chewed them raw. Even to this day, the pods of mesquite trees are a preferred treat for birds and squirrels in the neighbourhood.
Mesquite pods are considered to be a super food that contains elevated amounts of protein, but has a very low glycemic index. In addition, mesquite is gluten-free and an excellent source of several essential minerals, including iron, calcium, potassium, manganese, zinc and amino acid lysine People with diabetes will find mesquite very useful, as it is an excellent resource of tannins, soluble fiber, mucilaginous polysaccharide gums and inulin (a polysaccharide) that are effective in preventing as well as improving diabetes.
It is said that the bark of mesquite trees also encloses tannins and provides a brown-hued gum, which can be used in the form of a glue and varnish. In addition, this gum is also reported to possess therapeutic properties and is used in the form of a medicine.
Habitat and cultivation
The Prosopis pallida is a large tree indigenous to the north-western regions of South America, especially Colombia, Peru and Ecuador.
This particular mesquite species is found growing extensively all over the northern regions of Australia, especially in the inland areas. It is also very common in the north-western regions of Queensland and found growing naturally in the central areas of the country’s Northern Territory. It grows in a scattered manner in the central and southern Queensland, coastal areas of north-western Australia, inland in the northern region of New South Wales and also in different areas of the Northern Territory.
This species has also been introduced into Brazil, Puerto Rico, Hawaii, India, the Marquesas, New Guinea and the southern regions of Africa, where it is found growing in wild. Often, mesquite trees are found growing in wet places where the environment is somewhat arid or semi-arid, such as in gullies, down the creeks, in intermittent stream-beds and others. This plant can also be found growing beside the roads, in meadows, close to habitations as well as in open forest lands.
Sometimes this mesquite species was also employed as a substitute for woodlands with a view to prevent soil erosion and when the plants became established, they took over the surroundings. Long back, this species was introduced in places like Hawaii, Puerto Rico and some places in Australia, such as Queensland and New South Wales and over the years, it has become a natural plant in these places. In 1828, the first mesquite tree was introduced in Hawaii and, over the years, it has turned out to be an omnipresent shade tree and has invaded the Hawaiian Islands as a weed. Nevertheless, these trees are also useful as they provide firewood for cooking as well as heating.
Mesquite tree is mainly propagated by its seeds. Nevertheless, the existing stands of this plant can also turn out to be denser by means of layering and suckering. Generally, the seeds of this species are scattered after they are eaten by animals. In addition, the seeds are also carried by the flood waters and when they lie on the ground they also get stuck to machinery and vehicles. They are also spread by means of various activities by humans.
The kiawe tree grows to a reasonable height and bears spines and greenish-yellow blossoms on spikes. The plants bear elongated pods that are packed with small brown colored seeds. As this species has the ability to proliferate by two different means, it is an extremely invasive plant. Kiawe can easily reproduce in large numbers by means of the vast amount of its seeds, often dispersed far and wide, and also by means of suckering that creates dense monotypic (just one type) of stands that provides shade to other plants in the vicinity and retards their growth. The elongated taproots of kiawe help it to survive excellently in arid environments. The taproots of this plant are extremely effectual in drawing moisture from the soil. Often they extract so much moisture from the soil that they may even kill the plants growing in the vicinity by leaving them without enough water to survive. This species may be found growing naturally in places where none other plants grow, for instance, arid, sandy, debased slopes; disturbed areas; salty soils and even mountainous cliffs.
Mesquite contains two important alkaloids: prosoflorine and prosinine. Additionally it contains almost 8% of proteins, 46% of natural sugar, vitamins B complex, minerals such as magnesium, calcium, potassium, iron (small amounts), manganese (small amounts), chrome and copper also in small amounts.