Determining the 'most common flower in the world' is not a simple and straightforward answer, as it depends on multiple factors including geographic location, climate, soil type, human activities such as horticulture and agriculture, and the natural distribution of plants. However, if we consider from the perspective of being widely present globally, easy to grow, and frequently touched by humans, there are several types of flowers that can be considered quite common and widespread.
1. Wildflowers, such as dandelions, cornflowers, violets, etc., can grow naturally in many parts of the world without special care, so they are very common in many regions.
2. Ornamental flowers such as roses, tulips, chrysanthemums, etc. are widely planted in parks, gardens, and private residences due to their beauty and diversity, and can therefore be seen in many parts of the world.
3. Agricultural crop flowers: such as sunflowers, rapeseed flowers, etc. These flowers are not only agricultural crops, but also often admired for their beauty. In areas where these crops are grown, they will become a very common landscape.
4. Street greening plants, such as cherry blossoms and osmanthus flowers, are widely distributed in urban streets and parks during the flowering season, becoming a part of the urban landscape.
However, it is very difficult to select the "most common" flower from them, as this requires specific statistical data and extensive geographical coverage. Moreover, the "most common" flowers in different regions may vary.
If we have to guess from a global, non-specific geographical perspective, we may tend to choose wildflowers or ornamental flowers that have a wide natural distribution or are widely planted by humans on a global scale. But this is still a subjective guess and there is no conclusive evidence to support it.
No flower can be definitively referred to as the 'most common flower in the world', as it depends on multiple complex factors.