The Manfrotto 055XPROB is a superlative tripod, especially for low-angle / macro work on the ground, and it's pretty inexpensive. It's not as light as the carbon fiber tripods, but it's not all that heavy.
Put a Really Right Stuff BH-40 on that, and you're good to go.
If weight is an object and money isn't, RSS is making some great carbon fiber tripods.
+1 055XPROB Very good for Macro work. it is solid and hefty. If you are weight sensitive, the Carbon fibre version is available for $$$ more. The best part is you can shoot grass while being at eye level with this.