I enjoy a warm cup of rooibos in the afternoon as it's naturally caffeine-free.

rooibos 是来自南非荷兰语的词汇，原意是"红色灌木"，指一种生长在南非的植物，其叶子常用来制作不含咖啡因的草本茶。这种茶在中文里音译为"路易波士茶"。