FABACEAE

-

            1. SYSTEMATIC POSITION:
            Bentham & Hooker
            Division: Phanerogames (Seed Plants)
                  Class: Dicotyledones
                          Sub-class: Polypetalae
                                 Series: Thalamiflorae
                                       Order: Rosales
                                              Family: Fabaceae
           
            2. MORPHOLOGICAL CHARACTERS:
            Habit – Herbs, shrubs or trees, often climbing.
            Leaves – Compound, alternate.
            Inflorescence  – Racemose to cymose head or panicle.
            Flower – Hermaphrodite, actinomorphic or zygomorphic, slightly perigynous.
            Calyx – Sepals 4 or 5, free or united.
            Corolla – Petals 4 or 5, papilionaceous, aestivation vexillary or valvate or imbricate.
            Androecium – Stamens 10 or more, sometimes less, free or diadelphous.
            Gynoecium – Carpel one, ovary superior, unilocular, stigma capitates, style long, placentation marginal.
            Fruit – Legume or pod.
            Seed – Embryo large, cotyledon fleshy or leafy.
           
            3. FLORAL FORMULA: ⊕  or☿% Pα,K(4 or 5),C(4 or 5),A 10 or more,G1
            
            4. COMPARATIVE SYSTEMATIC POSITION AND AFFINITIES:
            Bentham & Hooker, Engler & Prantl and several others included the Fabaceae in the order Rosales. Bentham & Hooker and several other taxonomist divided the family Fabaceae into three sub-families like – Papilionaceae, Caesalpiniaceae and Mimosaceae. Hutchinson considered these three sub-families as a single family and placed in a single order Leguminales or Fabales.
            According to Hutchinson, of the three families, Cesalpiniaceae is the most primitive. According to him, it closest to Rosaceae and seems to have been derived from the rosaceous stock. He considered the fabales close to Sixifragales and derived from their immediate ancestors.
                5. ECONOMIC IMPORTANCE:
            1. Cicerarietinum (Gram), Lens culnaris (Lentil), Phaseolus aureus (Green gram), Pisum sativum (Pea), Arachis hypogaea (Ground nut), Cajanus cajan (Pigeon pea), Glycine max (Soyabean), Dolichos lablab (Broad bean) yields important food grains.
            2. Dalbergia sisso, Acacia melanoxylon, A. visco, Albizia lebbeck, A. procera, etc. yields valuable timber.
            3. Samanea saman (Rain tree) is planted as a shade tree on the road sides.
            4. Khair is obtained from the seeds of Acacia catechu.
            5. Cassia fistula (Gold mohur), Delonix regia (Indian laburnum) are planted as ornamental plants.

*************

Comments

Post a Comment

Popular posts from this blog

EQUISETUM - CLASSIFICATION, STRUCTURE OF SPOROPHYTE, REPRODUCTION, STRUCTURE OF GAMETOPHYTE AND FERTILIZATION

-
Image
A. CLASSIFICATION: Division – Sphenophyta     Class – Sphenopsida        Order – Equisitales            Family – Equisitaceae               Genus – Equisetum Equisetum commonly known as horsetails comprises about 25 species and is world-wide in distribution. Equisetum can grow in wide variety of habitats. Some species grow in damp and shaded places, others grow in ponds and marshes or in sandy soil, near the banks of rivers, etc. Some others are found to grow in exposed dry habitats, along the road side and railway embankments. Some of the common Indian species of Equisetum are – Equisetum debile , E. arvense , E. Diffusum , E. elongatum , etc. B. STRUCTURE OF THE SPOROPHYTE: 1. External structure:- The sporophyte, i.e., the plant body is well differentiated into – stem, leaves and roots – Stem – The stem is underground, horizontal and much branched, which often penetrates more than a meter into the soil. The rhoizome is jointed and provided with nodes and
Read more

PUCCINIA - CLASSIFICATION, VEGETATIVE STRUCTURE, REPRODUCTION, ECONOMIC IMPORTANCE

-
Image
            A. CLASSIFICATION Division – Mycota       Sub-division – Eumycotina             Class – Basidiomycetes                   Sub-class – Heterobasidiomycetidae                        Order – Uredinales                              Family – Pucciniaceae                                   Genus – Puccinia             The genus Puccinia is cosmopolitan in distribution and is a parasitic fungus causing diseases on many crop plants such as wheat, barley, oats, etc., and causes great loses to the cultivated crops. Puccinia is an obligate fungal parasite and are commonly known as ‘rust fungi’ because they produce ‘rust-like’, i.e., reddish-brown coloured spores in the form of rusty spots or streaks on stems, leaf-sheaths, leaves, etc., of the host plants.             The genus includes about 3000 species. Out of these, 147 species have been reported from India. Wheat rust disease has been extensively studied in India and is found to be caused by three different
Read more

SELAGINELLA - CLASSIFICATION, STRUCTURE OF SPOROPHYTE, REPRODUCTION, STRUCTURE OF GAMETOPHYTE, FERTILIZATION, MORPHOLOGY OF RHIZOPHORE OF SELAGINELLA

-
Image
A. CLASSIFICATION: Division – Lycophyta      Class – Lycopsida          Order – Selaginellales              Family – Selaginellaceae                  Genus – Selaginella The genus Selaginella is commonly known as “ Club-moss ” or “ Spike-moss ”. Selaginella is a large genus comprising about 700 species and is world-wide in distribution. Some species of Selaginella are found to grow in temperate regions but majority of them are found to occur in the rain forests of tropical countries. The species of Selaginella is found to grow on the ground, on damp, shaded and humid conditions. Some species are also occurs in arid regions of the world. Temperate species are found to grow on damp shaded sides of the hills. About 55 species are found to occur in India. Of these the common species are S. rupestris, S. chrysocaulos, S. pallidissima, S. jacquemonth, S. megaphylla, S. pentagona , etc. B. STRUCTURE OF THE SPOROPHYTE: 1. External structure:- The sporophyte, i.e., t
Read more