Research Advances on Native Economic Plants: Trees and Shrubs in Mexico
RATIKANTA МА1ТГ, HUMBERTO GONZALEZ RODRIGUEZ, and CH. ARUNA KUMARI
The paper narrates a brief review of research advances undertaken by the author and his team on various aspects of native economic plants and also trees and shrubs in Northeast Mexico. Research on native plants includes native crops species, medicinal plants, fiber-yielding plants, cactus spp. The research on medicinal plants in Northeast and highlands of Mexico involved the studies that dealt mainly on ethnobotany, pharmacognosy, phytochemistry, macro- and micronutrients of medicinal plants. Various research methodologies are discussed on different economic plants of Mexico.
The present review makes a synthesis of various aspects of applied biology of more than 30 woody plant species of a Tamaulipan Thom scrub, Northeastern Mexico on various aspects, such as variability in leaf traits, leaf anatomy, plant characteristics, wood anatomy, wood density, phenology, and few aspects of physiology and biochemistiy namely, leaf pigments, leaf epicuticular wax, trees with high nutritional values, carbon fixation, nitrogen and protein contents. The results show a large variability of all the morpho-physiological traits of the woody species related to the coexistence and adaptation of the woody species to the semiarid conditions of Northeast Mexico.
For more than 30 years as professor and research scientist in two universities, Universidad Autonoma de Nuevo Leeon and Universidad de las Americas in Botany Departments, I have been working on various aspects of economic plants namely, native crop species, medicinal plants, fiber yielding plants, cactus spp., and also on experimental biology of more than 30 woody trees and shrubs at Linares, Northeastern Mexico.
The results have been published as papers in different international journals and books mentioned in the references.
NATIVE ECONOMIC PLANTS, TREES AND SHRUBS
6.2.1 NATIVE CROPS IN SEMI ARID REGIONS OF NORTHEAST OF MEXICO
Researches have been undertaken on various aspects of several potential native crop species that are effectively utilized by local inhabitants as food sources. Chile Piquin, wild chili [capsicum annuum var aviculare (Dier)]. wild chili, Chile piquin [Capsicum annuum var aviculare (Dier)] is of high commercial value for great demand in foreign countries, like USA, domestic culinary values, and medicinal values. This wild chili is grown in its wild habitat on mountains and forests under the shades of trees.
The local inhabitants harvest this wild chili by cutting the branch bearing bunches of round to elongated chili. The seeds of wild chili possess seed dormancy and hard seed coat for which fanners cannot cultivate. The Local inhabitants transplant the plant and grow them in pots that supplies chili for their daily use. An efficient technique was developed to break the dormancy of this wild chili and induce germination.
A small number of seeds are mixed with cow dung extracts in a small flask. The flasks are kept at a low temperature of 4°C for about a week in a refrigerator. The low-temperature induced seeds are then sown superficially in trays that were filled with finely ground soil mixed with organic humus. These trays are given regular slight irrigations so as to keep the soil moist till emergence and growth of the seedlings. When the seedlings are 30 days old, they are transplanted into pots or trays or under the shadow of trees. Wild chili plant requires shade for good growth and productivity.
An efficient technique has been developed by us to break seed dormancy and induce germination. This involves to keep a small number of seeds mixed with extracts of cow dung in a small flask and then keeping it in a refrigerator at 4°C for 7 days and then the treated seeds are sown superficially in trays filled with finely ground soils mixed with organic humus. This needs to be irrigated regularly to keep the soil moist. When the seedlings are about 30 days, we transplant these in pots or trays or under the shadow of trees.
The plant requires shadow for its good growth and productivity. Besides, studies have been undertaken on ecophysiology of this wild chili that included distribution, botany, phenology, pollen viability, biochemistry of chili, macro- and micronutrients, nutritional values, drought resistance related to water potential of the plant (Maiti and Almanza, 1999).
6.2.2 AMARANTHUS SPP. IN SEMIAR1D REGIONS OF NORTHEAST MEXICO
Several species of Amaranthus grow in wild conditions in Nuevo Leon, Northeast Mexico.
Studies have been undertaken on botany, anatomy, microsporogenesis, and nutritional values of some species of Amaranthus. These studies have shown the presence of large variability in different characteristics among these Amaranthus species. A study on nutritional values of vegetable organs of different species of Amaranthus showed large variations in nutritional values. Few species, such as Amaranthus viridis, Amaranthus palmeri, Amaranthus retroflexus were found with high-nutritional values, which may be recommended for the nutrition of patients and children but needs to be confirmed.
Therefore, there is a necessity for domestication and cultivation of these selected species as vegetables for human nutrition. A few papers were published that have been mentioned in references.
6.2.3 PHASEOLUS SPP. PHASELULS VULGARIS
Beans are very important leguminous crops of high protein content as an important food crop in Mexico, Latin American countries and Asiatic countries. Different aspects of studies have been undertaken on botany and physiology of few wild spp. of Phaseolus that grew in Nuevo Leon. Research should be undertaken on the food values of these species.
6.2.4 BRASSICA SPP.
Different species of Brassica such as B. campestris, B. oleracea are important sources of edible oils in the world. We observed that two wild species of Brassica, B. campestris and B. oleracea, grow in wild condition. The studies have been undertaken by us on botany, phenology, and germination of these species (not published). We observed in the case of B. campestris that treating its seed in low temperature at 4°C break seed dormancy and induce germination, which needs to be confirmed in future studies. I observed that B. campestris was tolerant to cold when most of the plants are killed in one severe winter season.
A study has been made on chemical, nutritional, and functional characterization of Brassica campestris. Papers are published on these aspects.
6.2.5 WILD HELIANTHUS SPP.
Mexico is considered as the origin of sunflower, Helianthus. We observed that this species grows enormously in wild condition. Studies have been undertaken on distribution, botany, and germination of this species. Research needs to be directed on the domestication of this wild species of Helianthus.
6.2.6 MEDICINAL PLANTS
In Nuevo Leon many native medicinal plants at traditionally used in alleviating various diseases. We analyzed a few macro- and micronutrients of 44 medicinal species used for various diseases. We selected species with high values of macro- and micronutrients.
- 188.8.131.52 MACRONUTRIENTS
- A) Species containing high Potassium (K) content on average (mg g_1 dw): Opuntiaficus-indica (101.47), Plioradendron villosum (100.58), Moringa oleifera (95.59), Marrubium vulgare (91.27), Melia azadi- rachta (90.99), Hedeomapalmeri (76.50), Croton suaveolens (75.62), Agave macroculmis (78.45).
- B) Species containing high Magnesium (Mg) content (mg g_1 dw): Opuntia, Ficus indica (6.39), Melia azadirachta (3.41), Plioradendron villosum (2.29), Eriobotrya japonica (1.78), Bauhiniaforjicata (1.45).
- C) Species containing high Phosphorus (P) content (mg g_1 dw): Celtis laevigata (4.03), Carya illinoinensis (2.89), Phoradendron villosum (2.40), Arbutus xalapensis (1.78), Hedeoma palmeri (1.40), Matru- biutu vulgare (1.85).
- D) Apart from those mentioned above, there are certain species containing high carbon (C%). These have high carbon dioxide fixation ability. These include the species of Rhus viretis (50.35), Arbutus xalapensis (49.09), Cinnamomum verum (49.34), Tecoma stans (48.79), Eriobotrya japonica (47.98), Hedeoma palmeri (46.38), Moringa oleifera (45.96), Buddleja cordata (45.70), Cmya illinoinensis (44.27).
- E) The species with high Nitrogen (N%) are Moringa oleifera (6.25), Melia azarichta (5.85), Marrubium vulgare (4.56), Phoradendron villosum (4.92), Carya illinoinensis (3.76), Buddleja cordata (3.26), Celtis laevigata (3.01).
- F) Species containing high C/N ratio: Agave macroculmis (30.43), Arbutus xalapensis (26.45), Rhus virens (22.18), Cinnamomum verum (19.78), Croton suaveolens (19.37), Hedeoma palmeri (16.39), Eriobotrya japonica (15.83).
- 6.2.62 MICRONUTRIENTS
- A) Species with high Zinc (Zn) content (mg g'1 dw) Tecoma stans (216.31), Celtis laevigata (57.69), Arbutus xalapensis (55.20), Marrubium vulgare (53.54), Moringa oleifera (52.57). B). Species with high Copper (Cu) content (mg g_1 dw) Cinnamomum laevigata (33.88), Bauhinia fortificata (33.40), Cary’a illinoiensis (29.90), Etyobotria japonica (26.87).
- C) Species with high Iron (Fe) content (mg g_1 dw) Opuntia, Ficus indica (773.04), Tecoma stans (444.82), Melia azadirachta (374.78), Baidnnia forficata (347.58), Marrubium vulgare (334.23).
- 184.108.40.206 ELITE SPECIES WITH HIGH MACRO- AND MICRONUTRIENTS
- A) Potassium, Magnesium, and Phosphorus: Opuntia, Ficus indica, Phoradendron villosum, Moringa oleifera, Melia azadirachta, Celtis laevigata, Caiya illinoinensis.
- B) Nitrogen: Moringa oleifera, Melia azadirachta, Marrubium vulgare
- C) C/N: Agave macroculmis, Arbutus xalapeusis, Cinnamomum verum, Croton suaveolens, Hedeoma palmeri
- D) Zinc: Tecoma stans, Celtis laevigata, Arbutus xalapeusis
- E) Copper: Cinnamomum laevigata, Bauhinia forficata, Carya illinoi- nensis.
On the basis of macro- and micronutrients we recommend that Melia azadirachta, Opuntiaficus-indica, Phoradendron villosum, Moringa oleifera, Marrubium vulgare, Celtis lae'igata, Carya illinoinensis, Agave macroculmis, Cinnamonum verum, Croton suaveolens, and Hedeoma palmeri could be effectively used for the control of diabetes. Besides, while working in the Biology Department of Universidad de las Americas, I worked in collaboration with Dr. Eugenio Sanchez on etlmobotany and phytochemistry of few medicinal plants used in Puebla for various diseases.
6.2.7 FIBER YIELDING PLANTS
In arid lands of Northeast Mexico, Agave lecheguilla and Yucca carnerosana, are important sources of fiber, obtained from leaves and also important sources of income of poor arid farmers of this region.
The farmers collected the central young leaf cones, called cogollo, with the help of a hook and then extracted fibers from leaves manually by beating with iron bars or sharp knife or by machine where available. After extraction, they dry the fibers in sun. Leclmguilla fibers are strongest fibers used in a polishing machine. Except for few dasonomic studies, no other studies were available on this plant. With the help of students at bachelor, masters, and doctorate levels, we studied various aspects of this fiber plant, such as distribution, ecology, and developmental anatomy of the fibers of this species. Extensive exploitation of this species may lead to extinction.
Overexploitation of many of the native plants may lead to the extinction of these endangered economic plants but no attempts are made for the conservation and propagation of this valuable species of arid lands. On Yucca canierosana, the top of the trunk is cut completely and fibers are extracted manually. This leads to the death of the plants. We made only a few studies on developmental anatomy of the fibers of this plant. In addition, Henequen, Agavefourcroydes is cultivated for fiber extraction. A study has been undertaken on developmental anatomy of the fibers of this species.
6.2.8 CACTUS SPP.
Many species of cactus grow in arid lands of Mexico, many of which are endangered. While working in the Universidad las Americas, I undertook a series of studies with the help of my thesis students on various aspects of Cactus spp., botany, morphology, anatomy, phenology, and propagation of species. We developed a simple technique for germination and propagation of more than 60 species. The technique involves sowing the seeds on the soil surface in a tray filled with finely powdered soils mixed with sands and organic matter in a greenhouse.
The trays were covered with polythene sheets with few tube lights fixed above to give light. Cactus needs about 16 h light to induce seed germination. The trays are irrigated regularly with aspersion. Using this novel technique, a greenhouse owner in Puebla could propagate more than 60 species of Cactus with more than 90%.
6.3 RESEARCH ADVANCES ON EXPERIMENTAL BIOLOGY OF WOODY PLANTS OF A TAMAULIPAN THORN SCRUB, NORTHEASTERN MEXICO AND RESEARCH NEEDS
Studies have been undertaken on the biodiversity of leaf traits, leaf anatomy, plant characteristics, wood anatomy, wood density, phenology and few aspects of physiology and biochemistry namely, leaf pigments, leaf epicuticular wax, trees with high nutritional values, carbon fixation, nitrogen, and protein contents. It is suggested that large variations in all these ecophysiological and biochemical components could be related to the coexistence of these species in the semiarid environments of Northeast Mexico.
Some morpho-anatomical traits are considered to be related to adaptation to xeric environments, such as leaf surface, leaf lamina, petiole, venation system, and few wood anatomical and ecophysiological traits, such as pigments, epicuticular wax, leaf nutrients, carbon fixation, etc.
Forests play a great role in offering great service to mankind in reducing carbon dioxide from the atmosphere and converting it to carbon in wood as a source of energy through the process of photosynthesis and supply domestic and industrial products and function as a source of nutrients to grazing annuals.
6.3.1 LEAF TRAITS
There exists great diversity in leaf shape, size among woody species for coexistence (Maiti et al., 2015c). Woody plants possess two types of leaves, open canopy (all leaves exposed to sunlight) and close canopy where all leaves are not exposed to sunlight for the capture of solar radiation. It is hypothesized that variability in leaf canopy architecture may be related to photosynthetic efficiency and carbon fixation (which needs to be confirmed in future (Maiti et al., 2014b, 2016d).
6.3.2 LEAF ANATOMY
Leaf anatomical structures, such as leaf surface, leaf lamina, petiole venation pattern, play important roles in the taxonomic delimitation and adaptation of the woody plants to xeric habitats in Northeastern Mexico.
6.3.3 LEAF SURFACE ANATOMY
A study on leaf surface anatomy of 28 species of trees and shrubs showed large variations among species which could be related to drought resistance namely, abundance trichome, sunken stomata on the upper leaf surface, low frequency of stomata. These characteristics could be utilized in the taxonomic delimitation of the species. In the view of the above traits, the species selected for better adaptation to semiarid environments are Berberis chococo, Celtis laevigata, Condalia hookeri, Diospyros palmeri, Diospyros texana, Eben- opsis ebana, Ehretia anacua, Forestieria angustifolia, Havardia pallens, Helietaparvijlora, Kanvinskia humboldtiana, Sargantia gregii, Sideroxylon celastriana, Zanthoxylum fagara. The water relations and drought resistance of the species mentioned should be confirmed in a future study.
6.3.4 ANATOMY OF LEAF LAMINA
A study was undertaken to determine the variability in leaf anatomical traits and its relation to taxonomic delimitation and adaptation of the species to xeric environments. There exists a large variability of anatomical traits with respect to cuticle thickness, presence or absence, the length and compactness of palisade cells of trichomes, etc., which could be related to the taxonomic delimitation and the adaptation of the species to drought conditions. Some species, such as Kanvinskia humoldtiana, Lantana macropoda, Prosopis laevigata, Zanthoxylum fragara, Helieta paviflora, Acacia berlandieri, possess long and compact palisade cells, which are expected to be efficient in photosynthetic function and adaptation to drought. Future research needs to be directed in this direction (Maiti et al., unpublished).
6.3.5 PETIOLE ANATOMY
A comparative study on petiole anatomy of 36 woody species has revealed a large variability among species in various anatomical traits that can be used in taxonomic delimitation. Species were grouped on the basis of various petiole anatomical traits.
Only five species having large vascular bundle are efficient in the transport of nutrients and water, namely, Acacia berlandieri, Acacia rigidula, Diospyros palmeri, Fraxinus greggii, Gitaiacinn angustifolia, thick petiole (Acacia berlandieri, Acacia farnesiana, Berberis chococo, Bernardia myric- ifolia, Eysenhardtia texana), and mechanical tissues, such as thick cuticle (Acacia berlandieri, Celtis pallida, Condalia hookeri, Eysenhardtia texana, Gymnosperma glutinosum), a thick collenchyma (Acacia farnesiana, Berberis chococo, Bernardia myricifolia, Celtis pallida, Havardia pallens), and extra sclerenchyma bands that offer mechanical strength (Acacia berlandieri, Ebenopsis ebano, Eysenhardtia texana, Lantana macropoda, Prosopis laevigata, Xanthoxylum fagara).
The species having the combination of various desirable traits are expected to be more efficient in the physiological function and mechanical support such as Acacia berlandieri.
6.3.6 VENATION PATTERN AND VENATION SYSTEM
Venation gives mechanical strength to the leaf lamina and helps in the conduction of carbohydrates (photosynthates) and nutrients.
Among the species studied Eysenhardtia texana had maximum vein islet density, Ebenopis ebano, Caesalpinia mexicana, Kanvinskia hnmbold- tiana, etc., possessed medium density, whereas Guaiacum officinale, Amyris madrensis, Sargentia greggii had low density (Maiti et al., 2015h).
6.3.7 PLANT CHARACTERISTICS AND RELATIONSHIP
Woody plant species show large variations in various plant characteristics, such as type of leaf canopy, tree crown architecture, plant height, canopy cover, basal diameter, branching patterns, and branching density, and there exist relationships among these parameters (Maiti et al., 2015d, Maiti and Rodriguez et ah, 2016d).
220.127.116.11 TREE CROWN
Every tree species possesses a typical tree top crown architecture, such as globose, round, irregular architecture, with the association of branches and leaves which help in the capture of solar radiation. Few studies have been undertaken in these aspects.
18.104.22.168 BRANCHING PATTERN AND BRANCHING DENSITY
Branching pattern and crown architecture act as a solar panel in the capture of solar radiation. Three types of brandling patterns are found in trees and shrubs, such as monopodial, pseudopodial, and sympodial. The tree crown varies from globose, irregular, to conical patterns (Maiti et ah, 2015c).
A study has been undertaken on the perspectives of branching pattern and branching density in 30 woody trees and shrubs. The types of branching observed are monopodial, pseudomonopodial, and sympodial. The branching density observed through animation photography in the field has revealed the presence of three types of branching density, that is, high, medium, and low density. There exist differences in height, biomass, basal trunk, the angle of the primary and secondary branches (Maiti et al., 2015d).
22.214.171.124 WOOD ANATOMY
Wood is an industrial product of great economic importance derived from cambial activity in a tree. Wood is composed of secondary xylern vessels, wood fibers, wood parenchyma, and other products. Significant research inputs have been documented on wood anatomy. Several studies have been undertaken on variability in wood anatomical traits, such as porosity, vessel diameter, their orientations, wood parenchyma, the density of wood sclerenchyma, on the basis of which species may be selected for fabrication of strong furniture or papers, etc.
Most of the species are ring to semiring porous, few diffuse-porous. Fiber cells show large variations in the morphology, length, cell wall thickness, lumen breadth, on the basis of which species may be selected for strong furniture or paper pulp.
Many species possess narrow vessels, which are considered to work against cavitation or occulosis with small narrow vessels, mentioned have a strategy to adapt both to hot and cold climate against cavitation. The species having big vessel diameter may be susceptible to droughts, such as Celtis pallida, Caesalpinia mexicana or they may have a deep root system for adaptation to semiarid climates in northeast Mexico. Statistically significant differences are observed in all wood anatomical parameters among species studied (Maiti et al., 2016, Maiti et al., 2016d). A study has been undertaken on the variability of wood fiber cell morphology, length, breadth, the cell wall thickness in relation to their potential utility (Maiti et al., 2016; Maiti et al., 2016). Similarly, various studies in different aspects have been published (Maiti et al., 2015, Maiti and Rodriguez, 2015d, Maiti et al., 2016d).
126.96.36.199 REPRODUCTIVE BIOLOGY
In a forest ecosystem trees and shrubs start flowering, fruitification, and finally disperse seeds for maintenance of their life cycles. A study has been undertaken on flowering, fruiting phenology of 12 woody trees at Linares, Northeast Mexico (Maiti and Rodriguez, 2015a). There exists a large variability in the phenological stages among species. The results clearly demonstrate the variation in phenological time schedule among different species.
A study has been made on phenology and pollen viability of four woody species revealing that temperature plays an important role in pollen viability (Maiti and Rodriguez, 2015a).
- 6.3.8 PHYSIOLOGY AND BIOCHEMISTRY
- 188.8.131.52 LEAF PIGMENTS
A study has been made on pigment contents (chlorophyll and carotenoid) in 37 species of trees and shrubs in Northeast of Mexico during summer season (Maiti et al., 2016). Large variations were observed in the contents of chlorophyll (a and b and total) and also carotenoids among species. In a study there exists seasonal variation of leaf pigments in trees and shrubs in summer and winter seasons, the species contained lower pigments during winter seasons (Maiti et ah, 2016d).
6.3,8.2 EPICUTICULAR WAX
Several woody species in the semiarid regions of Northeastern Mexico possess waxy leaf surface owing to the presence of epicuticular wax. It has been documented that epicuticular wax helps in the reflection of sunlight from the leaf surface, thereby, reducing radiation load and maintaining lower leaf temperature and thereby imparting drought.
A study has been undertaken on the variability of leaf epicuticular wax. Few species were selected with high epicuticular wax namely, Foresteria angusti- folia (702.04 g/cm:), Diospyros texana (607.65 g/cm2), Bemardia myricifolia (437.53 g/cm2), Lencophyllum leucocephala (388.50 g/cm2), during summer. These species could be adapted under the semiarid condition for their capacity in the reflectance of radiation load, thereby, reducing gas exchange and probably impart drought resistance, water relations, etc. (Maiti et ah, 2015f).
184.108.40.206 MACRO-AND MICRONUTRIENTS
Woody plants possess various leaf nutrients that help in the growth and development of the species and serve as sources of nutrients for grazing animals. A study was undertaken to estimate six nutrients in the leaves, three macronutrients (K, Mg, and P), and three micronutrients (Cu, Fe, and Zn) of 25 woody species (Maiti et ah, 2016d).
Macronutrients and micronutrient contents (Cu, Fe, Mn, Zn, Ca, K, Mg, P, C, and N) of 10 native species exhibit large variations among species in the contents of the nutrients. К values ranged from round about 6.80-75.62 mg g'1; Mg content ranges 0.22-5.29 mg g'1, P from 0.09 to 2.43 mg g'1, Cu from 0.09 to 2.8 to 30.71 g gps'1, Fe from 66.32 to 276 g gps'1, Zn from 10.23 to 144.86 g gps'1. Croton suaveolens acquired highest level of P (2.43 mg g'1) and К (75.62 mg g'1), whereas Parkinsonia aculeata for Mg (5.29 mg g'1), Cordia boissieri for both Cu (30.71 g gps'1) and Fe (280.55 g gps'1), on the other hand, Salix lasiolepis for Zn (144.86 g gps'1).
These species could serve as excellent sources for ruminants and could adapt and grow well for high nutrient contents. The values of mineral contents were much higher than required by the grazing ruminants. The present study was undertaken to estimate six nutrients in the leaves, five macronutrients (P, Mg, К, C, N), and three micronutrients (Cu, Fe, and Zn).
Among macronutrients, P varied from 0.78 to 243 (mg g_1dw), the species containing high P are Croton suaveolens, 2.43; Eysenhardtia polys- tachya, 1.84; Prosopsis laevigata, 1.65; Parkinsonia aculeota, 1.56, Acacia farnesiana, 1.54, Mg varied from 0.22 to 9.45 (mg g“'d w). The species containing high Mg (mg g_1 dw) are Ehretia anactia, 9.45; Condalia hookeri, 6.50; Parkinsonia acideata, 5.29.
6.3.8A BIODIVERSITY OF LEAF CHEMISTRY (ON PIGMENTS, EP1CUT1CULAR WAX AND MACRO AND MICRONUTRIENTS)
A study was undertaken on pigments, epicuticular wax, and macro- and micronutrients of 15 woody species (Maiti et al., 2015) showing large variability in leaf chemical components. For example, species with high chlorophyll content were Ebenopsis ebano (1.755). Similarly, there were variations in chlorophyll a and chlorophyll b among species.
The species showing high-epicuticular wax load are Forestiera angusti- folia (702.04 g/cm2), Diospyros texana (607.65 g/cm2), Bernardia myricifolia (437.53 g/cm2). There is a need to confirm the efficiency of these selected species for productivity and adaptation of the species to the environment (Maiti et al., 2016c, Maiti and Rodriguez, 2015b).
Carbon, nitrogen, and protein content. Gonzalez Rodrigue et al. (2015c) reported large variation in leaf carbon, nitrogen, and protein content among 44 woody species at Linares, Northeast Mexico. In this study, a few species were selected with high carbon fixation, namely Eugenia caryophyllata (61.66%), Litsea glanscensens (51.54 %), Rhus virens (30.35%), Gochantia hypoleuca (49.86%),Pinus arizonica (49.32%), Erybotrya japonica (4.98%) and Tecoma stans (47.79%).
It is recommended that some of these species with high-carbon sequestration capacity may be planted in carbon polluted areas to reduce carbon load from the atmosphere, in addition, these, high-carbon concentration species, could serve as a good source of energy.
In this study, few species were selected with high nitrogen content namely, Mimosa malacophylla (8.44%), Capscicwn annum wild chili (6.84%), Azadirachta indica (5.85%), Eruca sativa (5.46%), Rosamarinus officinales (5.40-%), Menthapiperata (5.40-%).
Few species were selected with high C/N ratio namely, Arbutus xalo- peusis (26.94%), Eryngium heterophyllum (24.29%), Rhus virens (22.52%), Croton suveolens (20.16%), which may be related to high production of secondary metabolites [Maiti et al. (2016))].