Vivipary germination is found in

Concept: Vivipary is a germination phenomenon in which the seed begins to germinate while it is still attached to the parent plant, producing a well-developed seedling (propagule) before it detaches and falls. It is an adaptation seen in plants growing in unstable, waterlogged, or saline substrates, where an ordinary dispersed seed would find it difficult to establish after falling.

Application: Mangrove plants (such as Rhizophora and Avicennia) grow rooted in saline, waterlogged, intertidal mud. Their seeds germinate directly on the parent tree into an elongated, pencil-like propagule. When this propagule eventually falls, it is already developed enough to pierce into the soft mud and anchor itself quickly, before the tide can wash it away. This is why vivipary is the defining germination adaptation of mangrove plants.

Cross-check — why the other groups do not fit:

• Aquatic plants generally disperse seeds or fruits through water without germinating on the parent; their adaptations concern floating/buoyancy, not premature germination.

• Xerophyte plants are adapted to conserve water (reduced leaves, sunken stomata, thick cuticle) rather than to germinate early on the parent.

• Shrubs, as a general growth form, show no premature-germination adaptation; germination normally begins only after seed dispersal, as in most flowering plants.

Hence, vivipary germination is found in mangrove plants.