Clumps (leaves) identified by the Dendrogram method. Here we use different colours to indicate different leaves for clarity. Each leaf has a unique ID. We divide the leaves into three groups, one group contains clumps that belong to the “spiral arm” of the cloud (red numbers), and the other group contain clumps that are outside the “spiral arm” (blue numbers). The third group contains clumps 2, 4 and 7, which exhibit clear evidences of ongoing star formation (red stars).