Current Affairs 11th Class

Category : 11th Class

Systematic position

        Division      :         Angiospermae

        Class            :         Dicotyledonae

        Subclass     :         Gamopetalae

        Series          :         Bicarpellatae

        Order          :         Polimoniales

        Family         :         Solanaceae

Habit : Mostly herbs (Petunia, Solanum nigrum, Nicotiana, Withania), shrubs, a few trees (Solanum grandiflorum or potato tree) or climbers (Solanum jasminoides or potato vine, Solanum dulcamara).

Root : Branched tap root system.

Stem : Usually the stem is erect, solid, cylindrical and branched. Occasionally, it is spinous (Solanum xanthocarpum, Datura stramonium, Lycium). In potato (Solanum tuberosum) underground stem is modified in to tubers.

Leaves : Cauline, ramal, exstipulate petiolate or sessile, alternate, sometimes opposite, simple, entire, pinnatisect in tomato (Lycopersicum esculentum). Venation unicostate reticulate, variegated in Solanum jasminoides.

Inflorescence : Axillary or extra axillary cyme. Solitary axillary in Physalis and Pentunia. Sub-sessile umbellate cyme in Withania somnifera, solitary in Datura.

Flower : Bracteate or ebracteate, pedicillate, complete, actinomorphic, rarely zygomorphic (e.g., Salpiglosis, schizanthus), bisexual, rarely unisexual (e.g., Withania coagulans) pentamerous, hypogynous.

Calyx : Sepals 5, gamosepalous, tubular or campanulate, persistent, accrecent (enlarging in fruit, e.g., Physalis, Withania), Valvate or imbricate, green or coloured, hairy.

Corolla : Petals 5, gamopetalous, tubular or infundibuliform, valvate, twisted in Datura, bilabiate in Schizanthus, scale or hair like outgrowth may arise from the throat of the corolla tube, coloured.

Androecium : Stamens 5, rarely 4 (e.g., Salpiglossis) or 2 (e.g., Schizanthus), epipetalous, polyandrous alternate to petals, filament inserted deep in the corolla tube, anthers dithecous, usually basifixed or dorsifixed, introrse.

Gynoecium : Bicarpellary, syncarpous, ovary superior, carpels placed obliquely in diagonal plane, generally bilocular (2-4 locular in tomato, 4-locular in Datura due to false septa), placentation axile, ovules many in each locules, placentae swollen, a nectariferous disc or lobes may be present, stigma capitate or bifid.

Fruit : A many seeded berry (e.g., Tomato) or capsule (e.g., Datura).

Seed : Endospermic with straight or curved embryo.

Floral formula :