Which of the following fruits is an example of a caryopsis?

Step 1: Analyze the question The question asks which fruit is a caryopsis. This is a classification of fruit types in plant biology.

Step 2: Explain the concept A caryopsis (also called a grain) is a dry, indehiscent, one-seeded fruit in which the fruit wall (pericarp) is fused with the seed coat (testa). It is typical of the grass family, Gramineae (Poaceae).

Examples: maize, rice, wheat, guinea corn (sorghum), millet, and oats.

Step 3: Check each option

• A. Cashew nut: The true fruit is a kidney-shaped nut (a dry, one-seeded fruit with a hard shell), attached to a fleshy swollen stalk (the cashew "apple"). It is not a caryopsis.
• B. Combretum: It has a dry, winged fruit, described as a samara-like or winged indehiscent fruit. It is not a caryopsis.
• C. Maize: It is a grass, and each grain is a single-seeded fruit with the pericarp fused to the seed coat. This is a caryopsis.
• D. Orange: It is a fleshy fruit, a type of berry called a hesperidium. It is not a caryopsis.
• E. Tridax: It belongs to the daisy family (Compositae/Asteraceae) and has an achene (cypsela) fruit with a feathery pappus. It is not a caryopsis.

Step 4: Answer The correct option is **C.

Tip: Remember "grasses = grains = caryopsis". Whenever you see maize, rice, wheat, millet, or guinea corn in a fruit-type question, think caryopsis. For the daisy family (Tridax, sunflower), think achene or cypsela.