IB 103: Lec 21 — Carnivores (**still need to fix some stuff)

Did carnivory evolve once or multiple times in plants?

Multiple times (independently across different plant lineages).

Are there any monocots that are carnivorous?

Yes, some monocots are carnivorous (e.g., certain species in the order Poales).

In what environments are carnivorous plants typically found?

Nutrient-poor environments (especially low nitrogen), like bogs & wetlands.

In what environments are carnivorous plants typically absent?

Nutrient-rich environments (they don’t need to invest in carnivory there).

Why do carnivorous plants evolve in nutrient-poor habitats?

To supplement nutrient intake (especially nitrogen & phosphorous) by digesting prey.

What is the main physiological trade-off in carnivorous plants?

They invest less in roots (nutrient uptake) & more in traps to capture prey.

What are the 5 major types of carnivorous plant traps?

1. Pitfall (pitcher traps)

2. Flypaper (adhesive traps)

3. Snap traps

4. Bladder traps

5. Lobster-pot traps

Which trap type is most common?

Flypaper (adhesive traps).

Which trap types evolved only once?

Snap traps & bladder traps

What are all carnivorous plant traps derived from?

Modified leaves

What structural features help pitcher traps capture prey?

• Slippery surfaces

• Downward-pointing hairs

• Digestive fluid at the bottom

• Bright colors/nectar to attract prey

What do glandular hairs in adhesive traps secrete?

• Sticky mucilage (to trap prey)

• Digestive enzymes (to break down prey)

What is the function of each secretion?

• Mucilage: traps insects

• Enzymes: digest nutrients for absorption

Why are trigger hairs important in snap traps?

They detect prey movement & trigger rapid closing of the trap.

What is the fastest movement observed in plants?

Suction trap in Utricularia (bladderwort)