Nutrition in Insectivorous Plants Plant Physiology Ch 8 Class 11

Nutrition in Insectivorous Plants (Notes)

Some plants add organic molecules (carbon-containing compounds from animals) to their food in addition to normal inorganic nutrients (minerals, water, CO₂).
They capture and digest insects/small animals to obtain these organic chemicals.

👉 Important Point: All insectivorous plants are true autotrophs (they make their own food by photosynthesis).
But their growth accelerates (increases faster) when they capture prey, because they get extra nitrogen compounds (proteins, amino acids) from animals.

How They Digest Prey

Insects are broken down by enzymes (special proteins that speed up reactions) secreted from leaves.
The digested products (like amino acids, nitrogen) are absorbed by the plant for growth.

Examples of Insectivorous Plants

**1. Pitcher Plant (Nepenthes sp.)**

Leaf modified into a pitcher (sac-like structure) partly filled with water.
The terminal portion forms a hood (covering part of the opening).
Stiff hairs around the rim prevent insects from escaping.
Insects fall inside and are digested by enzymes.

Nutrition in Insectivorous Plants Plant Physiology Ch 8 Class 11

**2. Venus Fly Trap (Dionaea muscipula)**

Each leaf has two lobes forming a trap hinged at one end.
Inner surface has trichomes (hair-like projections).
When touched, they trigger the lobes to close rapidly.
Bristles along the margin interlock so prey cannot escape.
Digestive glands secrete enzymes to break down the insect, then nutrients are absorbed.

**3. Sundew (Drosera sp.)**

Leaves covered with tentacles (tiny hair-like structures).
Each tentacle tip has a gland that secretes shiny sticky fluid called dew.
Insects are attracted by the plant’s odour and the shining drops.
Once trapped, tentacles curl around the insect.
Enzymes digest the prey, and nutrients are absorbed.

Summary

Pitcher Plant (Nepenthes) → pitcher-shaped leaf traps insects.
Venus Fly Trap (Dionaea muscipula) → rapid trap movement with hinged lobes.
Sundew (Drosera) → sticky dew drops on tentacles capture insects.
All are autotrophs, but capture prey to gain extra nitrogen for better growth.