Q.Take one flower of the family Solanaceae and write its semi-technical description. Also draw their floral diagram.

Family Solanaceae — a common example is Solanum nigrum (black nightshade / makoi).

Semi-technical description:

• Habit: Herbaceous annual.
• Root: Branched tap root system.
• Stem: Aerial, erect, cylindrical, branched, solid, hairy and underground in some (e.g. potato).
• Leaves: Alternate, simple (sometimes pinnately compound in tomato), exstipulate, with reticulate venation.

Floral characters:

• Inflorescence: Solitary axillary or cymose.
• Flower: Bisexual, actinomorphic (radially symmetrical).
• Calyx: Sepals five, united (gamosepalous), valvate aestivation; persistent.
• Corolla: Petals five, united (gamopetalous), valvate aestivation.
• Androecium: Stamens five, epipetalous (attached to the petals) and alternating with them.
• Gynoecium: Bicarpellary, syncarpous (carpels fused); ovary superior, bilocular, placenta swollen with many ovules; axile placentation.

Floral formula (in words): Bisexual; actinomorphic; Calyx five united; Corolla five united; Androecium five epipetalous; Gynoecium bicarpellary syncarpous with superior ovary. …

The family Solanaceae is often called the "potato family". A widely used example for its semi-technical description is Solanum nigrum (black nightshade, makoi); potato, tomato, brinjal, chilli, tobacco (Nicotiana), petunia and Withania (Ashwagandha) also belong here. A semi-technical description records the habit, then the vegetative characters, then the floral characters in an inward sequence, and finally condenses everything into a floral formula.

Habit

• Herbaceous annual (some members are shrubs or small trees).

Vegetative characters

• Root: Branched tap root system.
• Stem: Aerial, erect, cylindrical, branched, solid and hairy; underground and modified for storage in a few members (the tuber of potato).
• Leaves: Alternate, simple (pinnately compound in tomato), exstipulate, with reticulate (net-like) venation; often hairy.

Floral characters

• Inflorescence: Solitary and axillary, or a cymose cluster (as in Solanum).
• Flower: Bisexual, actinomorphic (radially symmetrical), hypogynous (ovary superior), usually pentamerous, and complete.
• Calyx: Sepals five, united at the base (gamosepalous), showing valvate aestivation; the calyx is persistent (remains attached to the fruit).
• Corolla: Petals five, united (gamopetalous), often wheel-shaped or bell-shaped, with valvate aestivation.
• Androecium: Stamens five, epipetalous (inserted on the petals) and alternating with the petals; anthers are usually dithecous.
• Gynoecium: Bicarpellary and syncarpous (the two carpels are fused); ovary superior, bilocular (two chambers), with a swollen axile placenta bearing many ovules; the two carpels are set obliquely to the median plane, a diagnostic Solanaceae feature.
• Fruit: A berry (tomato, brinjal) or a capsule (Datura).

Floral formula (spelled out, no symbols):

• The flower is bisexual.
• It is actinomorphic (radial symmetry).
• Calyx: five sepals, united (gamosepalous).
• Corolla: five petals, united (gamopetalous).
• Androecium: five stamens, epipetalous. …

Method: Building the Description Top-Down from the Floral Formula

Instead of memorizing a long paragraph describing Solanum nigrum feature by feature, work in the opposite direction: start from the compact floral formula and expand each symbol into its full sentence. This is faster to recall because you only need to hold five short symbols in your head, not five paragraphs.

The formula for a typical Solanaceae flower is: bisexual, actinomorphic, K(5), C(5), A5 epipetalous, G(2) superior.

Expand each piece in turn. Bisexual plus actinomorphic gives "the flower is bisexual and radially symmetrical." K(5), where the bracket means fused and the 5 means five sepals, gives "calyx of five fused sepals, valvate." C(5) follows the same logic for petals, giving "corolla of five fused petals, valvate." A5, epipetalous, gives "five stamens, attached to the petals, alternating with them." G(2), superior, where the bracket means the two carpels are fused and superior means the ovary sits above the other whorls, gives "bicarpellary syncarpous gynoecium, ovary superior, bilocular, axile placentation, with the two carpels set obliquely, a Solanaceae fingerprint." …