What the category actually means
Naturally caffeine-free botanicals contain no caffeine because the plant does not produce it: rooibos, honeybush, chamomile, peppermint, hibiscus, rooibos-based blends, and barley tea among many others. This is different from DECAFFEINATED tea, which is Camellia sinensis that has had most of its caffeine removed by a process and which retains a small residual amount. Both are sold as caffeine-free and only one of them is.
The botanicals that are not caffeine-free
Several plants sold as herbal infusions do contain caffeine, and the herbal shelf implies otherwise. Yerba mate contains a substantial amount. Guayusa and yaupon likewise. Cacao husk contains theobromine, a related compound, rather than caffeine. Barley tea, rooibos and honeybush genuinely contain none. Anyone choosing an infusion specifically to avoid caffeine needs to check the plant rather than the shelf it was on, and TeaHQ will record the distinction on each botanical record rather than relying on the category.
Two of the most-drunk examples
Rooibos, from a South African shrub, is the most widely drunk naturally caffeine-free botanical outside Europe’s chamomile tradition, and it takes milk in a way most infusions do not. Barley tea — mugicha in Japan, boricha in Korea — is roasted grain rather than a botanical infusion in the strict sense, drunk cold by the jug through summer across East Asia, and is one of the most-consumed non-tea drinks in the world despite being almost invisible in Western herbal ranges.
The limitation, stated plainly
The absence of caffeine is a compositional fact and is the only thing these plants share. It implies nothing else about them: a caffeine-free infusion is not automatically mild, not automatically suitable for everyone, and not automatically free of anything else worth knowing about. Those are properties of individual plants and will be recorded on individual plants.