Puer and matcha. Not all puers are calming but matcha always is for me.
For me, some pu erhs as t-curious said and japanese sencha also act as a great calming tea for me.
Puerh with lots of cha qi (only about 1 out of 3). For my personal notes, I rate for both taste and cha qi. Anything above 90 on cha qi tends to either put me into a meditative mood or make me sleepy.
Sencha is my “meditation tea.” Also, certain theanine rich oolongs can give that relaxative effect.
I really think if you want a tea for relaxation you have to look not to real tea but to various herbal teas such as Chamomile, Rooibos, and Chrysanthemum tea. One of those might tend to relax you I find that only the rarest of real teas will relax me, I suppose those with high Theanine.
Two Leaves and a Bud “Organic Chamomile Tea” is my go to relaxation herbal tea, otherwise I enjoy Jasmine Greens as my relaxation tea.
For herbals, I like chamomile, which I’m drinking right now lol!
Of course green tea. Maybe you could try a green tea called Yinhao Peony. A nice tea, with quiet fragrance of sweetness.
Liu Bao! Perfect on a lazy day
Lavender is a great one! I thought it would be weird to drink it because I’m so used to smelling it in cosmetics and bath products or whatever, but it’s actually really nice and soothing. I haven’t tried 100% lavender tea but it’s great in combo blends with other herbs like chamomile (if you make your own, be sure to use culinary grade lavender though, because a lot of lavender isn’t grown for eating so who knows what it has on it!).