China Naming Network - Weather knowledge - What is the word with catalpa in the middle of Jiang's name?

What is the word with catalpa in the middle of Jiang's name?

Jiang Zize Jiang Zisong Jiang Zibo Jiang Zipeng Jiang Zizhou Jiang Zitong Jiang Zihui Jiang Zichang Jiang Zirui Jiang Zitao Jiang Zinan Jiang Ziyuan Jiang Ziye Jiang Zibai Jiang Ziyu Jiang Zixuan Jiang Zixi Jiang Zihan Jiang Zijie Jiang Zihao Jiang. Zi Peng Jiang Zichi Jiang Zide Jiang Zihong Jiang Ziou Jiang Zichao Jiang Ziyou Jiang Zirui Jiang Zisi Jiang Zilin Jiang Zixiao Jiang Ziyao Jiang Zikai Jiang Zicai Jiang Zibin Jiang Ziao Jiang Ziyi Jiang