In the debate of which is more beautiful, a single stem or a cluster of plum blossoms, the answer is subjective and varies depending on personal preference. However, a cluster of plum blossoms often tends to be considered more beautiful due to its visual impact and symbolism.

The beauty of a cluster of plum blossoms lies in their collective charm and the sense of abundance they convey. When blossoms are grouped together, they create a striking visual display that can be more captivating than a single stem. This is because clusters tend to be more vibrant and dynamic, with a greater variety of colors and shapes. The collective beauty of a cluster can evoke a sense of harmony and balance, which is often more aesthetically pleasing.

Furthermore, the cultural significance of plum blossoms in East Asian art and literature adds to their allure. In Chinese culture, plum blossoms are often associated with resilience and purity, as they bloom in the coldest months of the year. A cluster of blossoms can symbolize the collective strength and beauty of a group, making it a powerful representation of unity and community.

Data from various studies on aesthetic preferences support the notion that clusters of flowers are generally perceived as more beautiful. For instance, a study published in the Journal of Environmental Psychology found that participants rated clusters of flowers as more beautiful than single flowers. The researchers attributed this to the "unity effect," where the collective beauty of a group is greater than the sum of its individual parts.

In conclusion, while the beauty of a single stem or a cluster of plum blossoms is subjective, a cluster tends to be considered more beautiful due to its visual impact, cultural significance, and the psychological effect of the "unity effect.