EUPHORBIACEAE

-

            1. SYSTEMATIC POSITION:
            Bentham & Hooker
            Division: Phanerogames (Seed Plants)
                 Class: Dicotyledones
                        Sub-class: Monochlamydeae
                               Series: Unisexualies
                                      Family: Euphorbiaceae
           
           
            2. MORPHOLOGICAL CHARACTERS:
            Habit – Mostly annual or perennial herbs, aromatic.
            Leaves – Alternate or sometimes opposite, simple or rarely compound, stipulate, hairy and sometimes replaced by glands, hairs and thorns.
            Inflorescence – Variable, often racemose and subsequent ones cymose or all cymose. Characteristic inflorescence is cyanthium.
            Perianth – Tepals 3-5 or 0, green and rarely petaloid, disc entire or variable number of glands.
            Androecium – Stamens 1-many, filaments branched or connate in many bundles, anther dithecous.
            Gynoecium – Carpel 3, syncarpous, ovary 2-4 locular, superior, ovules 1 to 2 in each loculus, placentation axile, style 3, each bifid, stigma 6.
            Fruit – Usually schizocarpic, regma splitting into 3 cocci, rarely drupe, capsule or nut.
           
            3. FLORAL FORMULA:   Male flower:      ⊕♂P3-5 or (5+5), A1-α                             
                                                         Female Flower: ⊕♀P3-5 or (5+5), G(3) or more
           
            4. COMPARATIVE SYSTEMATIC POSITION AND AFFINITIES:
            Euphorbiaceae is closely allied to the members of the order Malvales. This family is also related to the members of the order Gereniales and Sapindales on account of the nature of ovules. It is related to the family Sterculaceae in particular due to the presence of monoadelphous stamen, rudiments of stamens and carpels, androphore and gynophores occasionally and the nature of embryo.
            It has been suggested that the Euphorbiaceae arose from the Malvales. The members of Euphorbiaceae seems to be highly specialized in the presence of reduced flowers in many, flower like inflorescence (Cyathium) in Euphorbia and some other genera and milky latex.
            5. ECONOMIC IMPORTANCE:
            1. The bio-diesel crop Jatropa curcus belongs to this family.
            2. The rubber of commerce is obtained from the species of Hevea like H. brasilensis.
            3. Ricinus communis is the source of castor oil.
            4. Cultivated ornamental plants are Codiaeum variegatum, Pionsettia pulcherrima, Acalypha hispida, A. wilkesiana, etc.
            5. Plants with medicinal values are Croton spp., Acalypha indica, etc.
            6. The tuberous root of Manihot utilisima is the source of starch.
           
*************

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

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

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