Write about the key characteristics of Solanaceae.

Explanation

Vegetative Characters :
Habitat : These plants are mostly mesophytes. A few are xerophytes. (Solanum surattense).
Habit : Mostly annual or perennial herbs. Some are shrubs (Cestrum sps).
Root system : Tap root system.
Stem : It is aerial, erect and mostly herbaceous. Stem is an underground tuber in Solanum
Tuberosum (potato) : Bicollateral vascular bundles are present in the stem.
Leaf : Leaves are exstipulate, petiolate and show alternate phyllotaxy. They are usually or pinnately lobed. Venation is reticulate.
Floral Characters :
Inflorescence : It is usually cymose type. It may be terminal or axillary in position. In some species of Solanum, it is an axillary. In Datura, it is solitary and terminal, panicle in tobacco.
Flower : The flowers are bracteate or ebracteate, ebracteolate, pedicellate, actinomorphic, complete, bisexual, pentamerous and hypogynous.
Calyx : It consists of 5 speals which are fused (gamosepalous) and persistent (Capsicum, Solanum). The aestivation is valvate.
Corolla : The corolla consists of 5 petals and is gamopetalous. The aestivation is valvate or twisted. (Datura)
Androecium : There are five epipetalous stamens alternating with petals and are free. Anthers are dithecous, basifixed and introse. The dehiscence may be longitudinal (Datura) or porous (Solanum).
Gynoecium : The ovary is superior, bicarpellary and syncarpous. It is oblique in position due to the tilting of posterior carpel to the right and anterior carpel to the left at an angle of `45^(@)`. Usually bilocular occasionally unilocular (Capsicum). There are numerous anatropous ovules arranged on axile placentation on swollen placenta. The style is terminal and stigma is capitate.

Floral Formula :
Pollination : Flowers are usually protandrous. Some species of Solanum are protogynous. Cross pollination through insects (entomophily) is common.
Fruit : The fruit is mostly berry (Capsicum, Solanum, Lycopersicon, Physalis etc). It is septifragal capsule in Datura and Nicotiana.
Seeds : The seeds are endospermic and dicotyledonous.