SOLANACEAE

-

            1. SYSTEMATIC POSITION:
            Bentham & Hooker
            Division: Phanerogames (Seed Plants)
                 Class: Dicotyledones
                        Sub-class: Gamopetalae
                               Series: Bicarpellatae
                                      Order: Polemoniales
                                             Family: Solanaceae
           
            2. MORPHOLOGICAL CHARACTERS:
            Habit – Herbs or shrubs, mostly climbing vines.
            Leaves – Alternate, simple, exstipulate.
            Inflorescence – Usually an axillary cymes or sometimes axillary solitary.
            Flower – Bisexual, actinomorphic, hypogynous.
            Calyx – Sepals 5, united, persistent, valvate.
            Corolla – Petals 5, united, valvate.
            Androecium – Stamens 5 or sometimes 4 (didynamous), epipetalous.
            Gynoecium – Carpel 2, syncarpous, ovary superior, obliquely placed, bi-locular or imperfectly 4-locular by a false septum, ovules many in each locules, placentation axile.
            Fruit – A berry or capsule.

             


           4. COMPARATIVE SYSTEMATIC POSITION AND AFFINITIES:
            Bentham and Hooker have placed this family under the order Polemoniales. Hutchinson, Thorne, Cronquist put it under the order Solanales, while Takhthajan placed this family in the order Scorpulariales and Engler & Prantl in the order Tubiflorae.
            Solanaceae is allied to Convolvulaceae in both having pentamerous flowers, persistent calyx and bicarpillary ovary. However, Solanacese possess obliquely placed ovary and are predominantly erect, whereas these characters are absent in Convolvulaceae. In certain characters Solanaceae is closely allied to Scrophulariaceae, Boraginaceae and Polemoniaceae. The Solanaceae are considered to be the most closely allied to Scrophulariaceae from which they differ in the presence of bicollateral vascular bundles, usually actinomorphic corolla and four/five stamens.
                   5. ECONOMIC IMPORTANCE:
            Economically the family is fairly important. It comprises several plants of food value, medicinal, vegetables and ornamentals.
            1. Food yielding plants of the family are – Solanum tuberosum (Potato), S. melongena (Brinjal), Lycopersicon spp. (Tomato), Capsicum spp. (Chilli), etc.
            2. Drug yielding plants of the family are – Atropa belladonna, Withania somnifera, Datura stramonium, Hyoscyamus niger, etc.
            3. Ornamental plants of the family are – Petunia, Cestrum, Lycium, etc.
            4. Plants used for smoking and insecticide – Nicotiana tabacum, N. rustica, etc.

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

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