The Circle Repertory Company has assembled a trio of sensitively written and perceptively performed one-act plays under the title of ''Confluence.'' According to Webster, one of the meanings of the word is ''a stream uniting with another.'' The streams of thought that unite these playlets are the mutuality of feelings that attract the principal characters.
The common denominator of ''Confluence'' is a kind of comic ruefulness. Like most such collages, the overall aim sometimes exceeds the particular achievement. But thanks to the care - and the caring - that have gone into its making, this three-in-one program treats several of the ages of man with theatrical freshness and honesty.
John Bishop's ''Confluence,'' the centerpiece of the arrangement, is also the solidest in terms of character portrayal. It begins with ex-professional footballer Chuck Janola (Jimmie Ray Weeks) and his ambitious actress girlfriend, Kathy Milan (Katherine Cortez), picnicking on a patch of park in Confluence, Pa. After Kathy has taken off for rehearsal, Chuck is joined by Earl Douchette (Edward Seamon), once a baseball star, now a retired hardware store proprietor confined to a wheelchair. Their conversation becomes a verbal essay in counterpoint on the particularities of a life in professional sports - and what comes after the final inning or the last down.
Beth Henley wrote ''Am I Blue'' while still a student at Southern Methodist University. With all its evident debt to Tennessee Williams, this poignant comedy about two lonely innocents who meet in a squalid quarter of New Orleans sometime in 1968 speaks very much with its own voice
What gives the Henley portrait of two outsiders its theatrical juices is the characterization of the desperately spunky and dauntless Ashbe Williams (June Stein). As the reluctant youth coaxed and coerced by her determined hospitality, Jeff McCracken responds admirably to Miss Stein's wonderfully antic and finally touching Ashbe. B. Rodney Marriott directed.
''Thymus Vulgaris,'' the slightest of the one-act threesome, nevertheless sets the tone and tenor of the evening. Lanford Wilson is dramatizing what time and vicissitude have done to a much married trailer denizen (Pearl Shear) and her prostitute daughter (Miss Cortez), about to be abandoned at the altar by a rich California citrus grower. The players periodically step out of their parts (and the sleazy situation) to acknowledge the audience, but this mother-daughter reunion seems more calculated than believable. Like the other playlets, it is well performed by the aforementioned actresses and by Mr. McCracken as a casual cop. The versatile Miss Stein directed.
The settings by Bob Phillips, costumes by Joan E. Weiss, and lighting by Mal Sturchio all add to the pleasures of the occasion - as does watching the Circle Rep's superefficient stage crew change sets. Incidental music includes the Gershwins' ''Someone to Watch Over Me'' and Billie Holliday singing ''Am I Blue.'' And that's not bad!