“Tree” is a symbol referred to numerous times in all religious beliefs, and Babi and Baha’i religions are no exception. 
These are the two designs I worked on for the births of Baha’u’llah, the prophet of Baha’i Faith and The Bab, the forerunner to Baha’u’llah, which were a while ago. 
You can see the use of هـ=H letter in Baha’u’llah poster and ب=B letter in The Bab poster.  
Posters size is 40*50 cm and you only need to contact me to register your order if you would like these posters hung on your house walls.