There are several types of flowers that are commonly used to decorate cakes. However, it’s important to note that not all flowers are edible, and some can be toxic. If you’re planning to use flowers on a cake, make sure they are safe for consumption and haven’t been treated with any pesticides or chemicals. Here are a few flowers that are commonly used for cake decorations:

1. Roses: Roses are one of the most popular flowers used in cake decoration. They come in various colors and can add a romantic or elegant touch to your cake. Make sure to remove the thorns and use only the petals.
2. Pansies: Pansies have vibrant colors and a delicate appearance, making them a beautiful choice for cake decoration. They are edible and can be crystallized for an extra decorative touch.
3. Violets: Violets are small flowers with a lovely purple or blue hue. They can be used whole or as individual petals on cakes. Like pansies, violets can also be crystallized for a unique effect.
4. Marigolds: Marigolds have bright orange and yellow petals, which can bring a vibrant touch to your cake. Make sure to remove the bitter-tasting white base of the petals before using them.
5. Nasturtiums: Nasturtium flowers come in various colors and have a slightly peppery flavor, which can add a unique taste to your cake. They are also great for garnishing salads.
6. Lavender: Lavender flowers have a distinct aroma and a lovely purple color. They can be used sparingly to add a subtle floral flavor to cakes and desserts.

Remember to thoroughly wash and dry the flowers before using them on a cake. It’s also a good idea to consult with a knowledgeable florist or cake decorator to ensure that the flowers you choose are safe for consumption and suitable for your specific cake design.