An albuminous seed showing hypogeal germination is

The correct option is maize.

To understand why maize is the correct answer, let us break down the botanical terms used in the question: albuminous seed and hypogeal germination.

1. What is an Albuminous Seed?
Albuminous (or endospermic) seeds are those in which the endosperm is retained in the mature seed to provide nourishment to the developing embryo during germination. Maize (corn) is a classic example of an albuminous monocotyledonous seed, where a large portion of the seed consists of the endosperm. In contrast, seeds like gram and bean are exalbuminous (non-endospermic), meaning the endosperm is completely consumed during embryo development, and food is stored in the cotyledons.

2. What is Hypogeal Germination?
In hypogeal germination, the epicotyl elongates while the hypocotyl remains short. As a result, the cotyledons (or the single cotyledon/scutellum in monocots) remain buried beneath the soil surface. Maize exhibits hypogeal germination because its cotyledon remains underground, and only the coleoptile and plumule emerge above the soil.

Comparing the Options:
• Maize: Albuminous seed + Hypogeal germination (Matches both criteria).
• Bean: Exalbuminous seed + Epigeal germination (Cotyledons come above the ground).
• Castor: Albuminous seed + Epigeal germination (Cotyledons emerge above the ground and become photosynthetic).
• Gram: Exalbuminous seed + Hypogeal germination (Cotyledons remain underground, but it lacks endosperm).

Therefore, maize is the only seed among the choices that is both albuminous and shows hypogeal germination.