S Karthikeyan is well known among Bangaloreans who are even remotely interested in nature. A widely regarded wildlife researcher, birder and butterfly expert, he has also photographed and documented a user-friendly guide to the flowering trees of Bangalore. For a long time, it remained a post on his website, linked from several blogs including mine.
Karthik has now kindly consented to give his vast knowledge on the subject some mobility by making it a downloadable PDF. You can get it here.