Plants in motion is a comprehensive archive of time-lapse movies (Quicktime format) of plants germinating and growing, flowers opening, tropic responses and circadian movements. Some of the video is quite eerie. The plants really seem...erm...alive... The site also has a guide to making your own time-lapse film.
Botanical Record-Breakers - learn about the world's most poisonous plants, the fastest growing, the most painful, the oldest, the ongoing debate about the largest, and much more. Also discussed is the rare coconut pearl - botanical jewel, or hoax?
The delicate art of topiary, or "cutting trees into weird shapes". The people. The history. The outstanding. The bizarre, and the phallic (completely SFW). I grew up with a similar tree to the last one on my street, although ours had...uhugm... a knob on top; I believe the gardener responsible was too short to trim above a certain level...