NEW YORK -- When America first met Joaquin Phoenix, it was 1989 and he was starring in Parenthood. And he was called ''Leaf.''  But that wasn't at all unusual, considering that his brother was named River and he has sisters named Rain, Summer and Liberty. Almost all of the Phoenix kids, children of a couple of nomadic ex-hippies who kicked around as fruit pickers and even missionaries in South America, were in show business. 

Then, with River's career on the rise and the Phoenix name becoming an acting phenomenon to rival the Culkins, Leaf walked away from the biz. ''I didn't work,'' he said. ''I traveled around with my dad. Went to Mexico. I just grew up, basically. I lost my virginity. How's that?'' 

And when he re-emerged, in 1995's To Die For, he wasn't Leaf anymore. He was Joaquin. 

His brother had urged him to change his name back to Joaquin,  he said, but he didn't really care. ''I was just 'Leaf,' you know?" 

''But traveling through Mexico, I changed it. Here's the thing. There's ojo, ajo and hoja (in the Spanish language). That's 'eye, garlic and leaf.' So I was always messing it up with like, 'What's your name?' 'Garlic.' 'What's your name?' 'Eye.' They'd roll their eyes and laugh at me.  'It seemed like a good idea to change it back.'' 

To Die For served notice that the younger Phoenix brother was as good an actor as River. Enough time had passed where Joaquin could handle the questions about River's death from drugs and a career that began as ''River's kid brother.'' 

''If someone wants to write about me being in my brother's shadow, that's their prerogative. I can't worry about it,'' Phoenix said. ''I'm very proud of my brother.'' 

Phoenix is 23. His new film, Inventing the Abbotts, is his first star vehicle, a film in which he plays the romantic lead. In Doug Holt, Phoenix gets to portray a serious, romantic young man who learns to move out of his brother's shadow.  ''I don't really compare myself with the work,'' Phoenix said. ''I have no need to compare myself to the guys I play. There wasn't anything I could draw on to play this guy.'' 

But the Abbotts director, Pat O'Connor, said that Phoenix has had ''a very interesting life, which he brings to bear in the movie.''  Doug is ''an observer, a very perceptive person,'' Phoenix said.  ''You keep that sort of idea in the back of your mind and know that about him as you're playing him. In film, we tend to think of characters being just one thing: a journalist, for instance. But really, they're all just facets of who you are. I think you can concentrate on playing one part of the person too much.'' 

That's one of his gripes about working in the movies. 

Phoenix said that Hollywood's tendency to ''get you to do what you just did'' again was a problem after To Die For. 

In that Gus Van Sant film, Phoenix played a confused young man who is seduced by a beautiful woman (Nicole Kidman) into killing her husband. ''The key description of the character was 'inbred,' '' Phoenix said. ''That told me how to play him. I got hair extensions. I wanted to look like Billy Ray Cyrus.'' 

But after that, he ''got a lot of offers to play other trailer-park  kids,'' he said.  ''My favorite was a movie of the week about an older woman who seduces her student to kill her husband, which I thought was really original."

''I got some decent scripts. It's strange why you decide to do the things you do. I would think that if I had gotten Inventing the Abbotts now, I would do it again. It touched me. But I don't  know why.'' 

As fate would have it, Inventing the Abbotts was where Phoenix met and fell in love with his girlfriend, co-star Liv Tyler. 

''Liv is a darling,'' he said. ''I went out and did a screen test in L.A. She read with me. What can I say? Her honesty stands out. She's very real. You see that on the screen, too. She's right there. She's so genuine. We hit it off right away.'' 

Phoenix is suddenly a hot commodity in the movies. Fan magazines have picked up on his smoldering, rebellious looks. And he has a major role in Oliver Stone's latest film, U-Turn, also starring Sean Penn. 

''It's a film noir. Sean Penn is this drifter who comes into this little town, and I'm one of the townies who makes him realize how much he needs to leave the town. My character is just a drama queen. Tight jeans, hair sticking up about two feet high, TNT shaved into the back of my head, black boots. This kid is nuts, a small-town bully living in a dream world. He's one of these people who feels the camera is on him all the time, that he's being watched and recorded.'' 

The Phoenix family remains active in the movies. Joaquin's sister Summer just finished an independent film.  Rain, one of the stars of Even Cowgirls Get the Blues, is  playing music and still looking for acting work. 

Joaquin said he's happy to find himself in what has become the family trade. 

''I guess I feel I'm being productive and creative when I act. Everybody needs that: photographers, writers. I feel so happy when I'm working. It's what I want to do. Other than that, I can't analyze it.'' 
 
 
 

Published April 4, 1997