SEXUAL REPRODUCTION IN PLANTS
What is sexual reproduction in plants? In flowering plants, the flower is the reproductive organ which is a specialised shoot consisting of a modified stem and leaves. The stem-like part is the pedicel and receptacle, while modified leaves form corolla and calyx.
Structure of a flower
- A typical flower consists of the following parts:
- made up of sepals.
- They enclose and protect the flower when it is in a bud. Some flowers have an outer whorl made of sepal-like structures called epicalyx.
Consists of petals. The petals are brightly coloured in insect – pollinated flowers.
- Is the male part of the flower. It consists of stamens.
- Each stamen consists of a filament whose end has an anther.
- Inside the anther are pollen sacs which contain pollen grains.
- Is the female part of the flower.
- It consists of one or more carpels.
- Each carpel consists of an ovary, a sty le and a stigma.
- The ovary contains ovules which become seeds after fertilisation.
- A monocarpous pistil has one carpel e.g. beans.
- A polycarpous pistil has many carpels.
- If the carpes are free, it is called apocarpous as in rose and Bryophyllum,
- In carpels that are fused it is called syncarpous as in Hibiscus.
- A complete flower has all the four floral parts.
- A regular flower can be divided into two halves by any vertical section passing through the centre. e.g. morning glory.
- Irregular flower can be divided into two halves in only one plane e.g. crotalaria.