Q.Define the following terms:

• (a) Aestivation — the mode of arrangement of sepals or petals in a floral bud with respect to the other members of the same whorl (types: valvate, twisted, imbricate, vexillary).
• (b) Placentation — the arrangement of ovules within the ovary (types: marginal, axile, parietal, basal, free central).
• (c) Actinomorphic — a flower that can be divided into two equal radial halves in any radial plane passing through the centre; i.e. radially symmetrical (e.g. mustard, datura, chilli).
• (d) Zygomorphic — a flower that can be divided into two similar halves only in one particular vertical plane; i.e. bilaterally symmetrical (e.g. pea, gulmohur, bean).
• (e) Superior ovary — an ovary that occupies the highest position while the other floral parts are situated below it; the flower is then said to be hypogynous (e.g. mustard, china rose, brinjal).
• (f) Perigynous flower — a flower in which the gynoecium is situated in the centre and the other floral parts are arranged on the rim of the thalamus almost at the same level, so the ovary is said to be half inferior (e.g. plum, rose, peach).
• (g) Epipetalous stamen — a stamen that is attached to the petals (e.g. brinjal).

• (a) Aestivation

  • The mode of arrangement of sepals or petals in the floral bud with respect to the other members of the same whorl.
  • The main types are valvate, twisted, imbricate and vexillary.

• (b) Placentation

  • The arrangement of ovules within the ovary.
  • The types are marginal, axile, parietal, basal and free central.

• (c) Actinomorphic

  • A flower that, when divided vertically through the centre in any radial plane, produces two equal halves.
  • Such a flower is said to be radially symmetrical. Examples: mustard, datura, chilli.

• (d) Zygomorphic

  • A flower that can be divided into two similar halves only in one particular vertical plane.
  • Such a flower is bilaterally symmetrical. Examples: pea, gulmohur, bean, Cassia.

• (e) Superior ovary

  • An ovary that occupies the highest position, with the other floral parts (calyx, corolla and androecium) situated below it on the thalamus.
  • The flower bearing such an ovary is described as hypogynous. Examples: mustard, china rose, brinjal.

• (f) Perigynous flower

  • A flower in which the gynoecium is situated in the centre and the other floral parts are borne on the rim of the thalamus almost at the same level as the ovary.
  • The ovary here is said to be half inferior. Examples: plum, rose, peach.

• (g) Epipetalous stamen

  • A stamen that is attached to (fused with) the petals.
  • Example: brinjal.

Method: Grouping the Seven Terms by What They Describe

Rather than memorizing seven isolated definitions in list order, sort them into three functional groups based on what part of the flower each term is describing. This turns a long list into three short, related clusters.

Group 1, arrangement within a single whorl (2 terms):

• Aestivation = how sepals/petals of the same whorl overlap each other in the bud.
• Placentation = how ovules are arranged within the ovary. Both describe an internal packing arrangement of like structures.

Group 2, symmetry and position, described as opposite pairs (4 terms):

• Actinomorphic vs zygomorphic: this pair is about symmetry. Ask "can I cut this flower into two equal halves through any radial plane, or only one particular plane?" Any plane gives actinomorphic (mustard); only one plane gives zygomorphic (pea).
• Superior ovary vs perigynous flower: this pair is about vertical position. Ask "is the ovary the highest thing on the thalamus, or is it level with everything else?" Highest gives superior/hypogynous (mustard); level gives perigynous (plum).

Group 3, a single structural fact (1 term):

• Epipetalous stamen simply means "stamen glued to the petal." No pair needed, it is a standalone attachment fact.

By clustering the seven terms this way, you only need to remember three questions to answer all seven: how do same-whorl parts overlap or attach, through how many planes can I symmetrically cut the flower and where does the ovary sit vertically, and is the stamen fused to the petal.

This grouping method converts rote memorization into a small number of diagnostic questions, each of which unlocks two or more of the seven terms at once, making it far easier to recall accurately during an exam.