This pretty pattern is called "Bamboo", and is also known as "Bamboo and Rock". It was first used by Spode in 1806, but this color (a hand painted gold and translucent green over the transfer) came along later...about 1812. It is Pattern 1653,
I was disturbed that this Bone China teapot was not marked "Spode" (only 1653 hand painted in green), until I found the photo of this shape (plate 973, page 163) of a Spode "New Oval Shape" teapot in " A Directory of British Teapots", by Berthoud and Maskell. That one also had only the pattern number written in green. Further research proved that this pattern number 1653 is definitely Spode's "Bamboo" pattern.
This teapot also has the "high thumb rest, and large flattened dome strainer" mentioned in the book above. It is about 10-1/2" from handle to spout.
The teapot is in good condition. There are 2 "nibbles" to the spout. (See photo.) What I thought was a short hairline crack in the collar proved (under a black light examination) to be a very professional small repair. (See photo.) No other chips or cracks. There are some scratches and chips to the green enamel. I believe this teapot to be usable.