Step 1: Understanding Secondary Growth.
Secondary growth refers to the growth that occurs after the primary growth phase, involving an increase in the girth of plants through the activity of lateral meristems, such as the cambium.
Step 2: Analyzing the Options.
- (A) Triticum: Wheat (Triticum) does not exhibit anomalous secondary growth; it undergoes primary growth.
- (B) Oryza: Rice (Oryza) also does not show anomalous secondary growth. It is typically monocot, which generally lacks secondary growth.
- (C) Zea: Corn (Zea) is a monocot and does not show anomalous secondary growth either.
- (D) Dracaena: Dracaena, a dicot, shows anomalous secondary growth due to the activity of the cambium, which is not typical for monocots.
Step 3: Conclusion.
The correct answer is (D) Dracaena, which shows anomalous secondary growth.