I'm sorry, but that site is in error. I studied Japanese for many years and earned a minor in Japanese as well as a BA and MA in Linguistics, so I feel qualified to comment on this.
Iva is not a Japanese word or name. The Japanese language does not contain the sound /v/. The Japanese word for "yew tree" is "ichii."
Unfortunately, there is a lot of misinformation about the meanings and origins of names on the Web. It's necessary to use caution and verify what you find through other sources.
ETA: I just looked through the other "Japanese names" sections of "Babynology" and there are so many errors I can't even begin to mention them all. For instance: Fujita (a surname) is listed as a girl's name; Vini (impossible in Japanese) is included as a boy's name;
Akira (primarily used for males) is called a "top Japanese girl's name," and so forth. That site is a very unreliable source.
This message was edited 5/27/2008, 9:13 AM