Question

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

Answer 1

(1) Family Fabaceae/Papilionaceae (pea plant)
Fabaceae/Papilionaceae is a sub-family of the Leguminoseae family.

Vegetative features:
Habit: Pinnately compound, alternately arranged with leaf tendrils with the pulvinus present at the leaf base along folacious stipules.
Root: Tap root system with root nodules.

Floral features:
Inflorescence: Racemose, generally axial than terminal
Flower: Zygomorphic and bisexual flowers are found
Calyx: It contains five sepals which are gamosepalous while aestivation is imbricate.
Corolla: It contains five petals (polypetalous) with vexillary aestivation.
Androecium: It consists of ten anthers that are diadelphous with dithecous anthers.
Gynoecium: Monocarpellary superior ovary which is unilocular with marginal placentation.
Fruit: Legume pod with non-endospermic seeds

Floral formula:

Economic importance: Peas are used as vegetables for making various culinary preparations.

 

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(2) Flowers of Solanum nigrum
Family Solanaceae

Vegetative features:
Habit: Erect, herbaceous plant
Leaves: Simple, exstipulate leaves with reticulate venation
Stem: Erect stem with numerous branches.

Floral features:
Inflorescence: Solitary and axillary Flowers: Actinomorphic, bisexual flowers
Calyx: Calyx is composed of five sepals that are united and persistent. Aestivation is valvate.
Corolla: Corolla consists of five united petals with valvate aestivation.
Androecium: It consists of five epipetalous stamens.
Gynoecium: It consists of bicarpellary syncarpous superior ovary with axile placentation.
Fruits: Berry
Seeds: Numerous, endospermous

Floral formula:

Economic importance: Used for medicinal purposes.

Answer 2

Habit & Vegetative characters

• Habit: Herb, erect; annual/perennial.
• Root: Tap root, branched.
• Stem: Aerial, herbaceous, green, branched, solid, cylindrical.
• Leaves: Alternate, simple, exstipulate, petiolate; lamina ovate, entire to shallowly toothed; venation reticulate.

Inflorescence

• Axillary, cymose (often extra-axillary dichasial/solitary clusters).

Flower (diagnostic)

• Bracts: Usually present (bracteate).
• Symmetry: Actinomorphic (\(\oplus\)).
• Sex: Bisexual (⚥).
• Inserts: Hypogynous.
• Merosity: Pentamerous (5 in each perianth/androecium whorl).

Calyx

• \(K(5)\) — sepals 5, gamosepalous, small, persistent; aestivation valvate.

Corolla

• \(C(5)\) — petals 5, gamopetalous, rotate (wheel-shaped) and white; lobes 5; aestivation commonly valvate (plicate in some genera).

Androecium

• \(A_5\) — stamens 5, epipetalous, alternating with corolla lobes; filaments short.
• Anthers dithecous, basifixed, introrse, often connivent (forming a cone), dehiscing by apical pores (poricidal).

Gynoecium

• \(G\underline{(2)}\) — bicarpellary, syncarpous; ovary superior, usually bilocular (may appear 2–4 locular); placentation axile; style 1; stigma bilobed.

Fruit & Seed

• Fruit a berry with many seeds; seeds albuminous, embryo curved.

Floral formula: \[ \mathrm{Br}\; \oplus\; \text{⚥}\; K(5)\; C(5)\; A_5\; G\underline{(2)} \quad \text{(ovary superior, axile placentation)} \]

Floral diagram (schematic)