Alice Walker: her own woman; In Search of Our Mothers' Gardens, ''Womanist Prose,'' by Alice Walker. New York: Harcourt Brace Jovanovich. 393 pp. $14.95. The Color Purple, by Alice Walker. New York: Pocket Books. 251 pp. $5.95. (Paperback.) You Can't Keep a Good Woman Down, by Alice Walker. New York: Harcourt Brace Jovanovich. 167 pp. $10.95. Meridian, by Alice Walker. New York: Pocket Books. 220 pp.$3.95. (Paperback.) In Love and Trouble, by Alice Walker. New York: Harvest/Harcourt Brace Jovanovich. 138 pp. $2.95. (Paperback.) Revolutionary Petunias, by Alice Walker.New York: Harvest/Harcourt Brace Jovanovich. 70 pp. $3.75. (Paperback.) The Third Life of Grange Copeland, by Alice Walker. New York: Harvest/Harcourt Brace Jovanovich. 247 pp.$4.95. (Paperback.) Once, by Alice Walker. New York: Harvest/Harcourt Brace Jovanovich. 81 pp. $2. 95.

Alice Walker is currently our most celebrated woman writer. Within the past few months, she has been featured and photographed in such diverse mass media as Vanity Fair, People, and the New York Times Magazine. Her most recent novel, ''The Color Purple,'' has been a consistent best seller and received the double honor of the Pulitzer Prize and the American Book Award. Her part in the rediscovery of black woman writer Zora Neale Hurston, and the long-overdue attention paid to black women writers within the past few years, have undoubtedly contributed to her prominence. Her latest book, ''In Search of Our Mothers' Gardens,'' a collection of essays and lectures, reinforces that prominence and clarifies the themes of her earlier writings, allowing her audience to reconsider both the value of her work and its literary heritage.

''In Search'' is dominated by the presence of Zora Neale Hurston, whose research and experience with voodoo and anthropology shaped Walker's short story ''The Revenge of Hannah Kemhuff,'' as well as much of her other writing. In the long essay ''Looking for Zora,'' Walker writes movingly and with humor of her visit to Eatonville, Fla., where Hurston was born and where she eventually returned at the end of her life. There, Ms. Walker introduced herself as Hurston's niece, and so met people that Hurston knew. As Hurston's presence returns often in this collection, so do those of Walker's characters and family members. There is generally a blunt honesty in Walker's work and these essays spare neither her family nor herself. She writes of the double standard of sexual conduct within her family, and her estrangement from her father, which lasted until after his death.

''In Search'' is also a literary book, whose precision and economy of language in some ways recall the essays of Flannery O'Connor, although Walker's book is thematically arranged and demonstrates her growth and importance as a feminist, black woman, and literateur. She writes of her literary influences: Colette, Jane Cooper, Muriel Rukeyser, Margaret Walker, Jean Toomer, and, of course, Zora Neale Hurston. Other people represented here include her former husband, her daughter, and other family members, and her experiences with and about them well explicate the characters in her novels and poems. ''In Search'' seeks answers to the questions posed in her fictions and poems and, as it covers the 15 years of her literary career, demonstrates the process and development of an American writer.

The poems in Walker's first book, ''Once,'' owe much to the Japanese haiku. They are pictures of Africa's landscapes, the harshness of the early civil rights movement, and portraits of friends and lovers. As do many poems of that era, they show rather than tell of an immediate experience.

''Revolutionary Petunias,'' Walker's second book of poems, dwells more specifically on family and regional experiences - histories of the people behind the civil rights movement, who will become even more destructive and heroic characters in her later fictions. Her poems in both collections do not contain the polemics of poets like Don L. Lee or Sonia Sanchez, who seemed to feel that a strong black family was the answer to racism, and that relationships within the black community were beyond reproach. Like Hurston, Walker was always aware of the problems of personal relations of her men and women and sought to understand, rather than excuse or ignore, them. She writes knowledgeably about sharecroppers, factory workers, blues singers, and the elderly and uses the poetic medium to isolate and study themes that are later developed in her novels and stories.

In her first collection of stories, ''In Love and Trouble,'' her women characters confront church, voodoo, men who love books more than they do their wives, and encounter death and visions of Jesus on a dirt road. Examples include ''The Welcome Table,'' ''To Hell With Dying,'' ''My Sweet Jerome,'' and the Hurston-influenced story ''The Revenge of Hannah Kemhuff.''

The title story of Walker's second collection, ''You Can't Keep a Good Woman Down,'' depicts a white rock singer and a black blues singer who age together in a relationship that is deeper than the cultures each represents but fails to understand. Also from this collection, ''Porn'' is a satire that is really about sexual relationships, and ''Fame'' is about an aging writer's bitterness. Other stories about rape and abortion dramatize the ambiguous relationship between racism and sexism, and the options provided to men in all circumstances regardless of race. Walker's stories do, nonetheless, suggest the possibility of reconciliation between the genders.

''The Third Life of Grange Copeland,'' ''Meridian,'' and ''The Color Purple'' form a trilogy of novels embracing generations of people living in the South but outside history. Grange Copeland, who deserts his family and later returns as a more responsible person, finds that his son lives a life even worse than the one he had left years before. ''Meridian,'' which is almost a continuation of ''Grange Copeland,'' has a young woman returning to the South for essentially the same reason that Grange Copeland had left and, in this way, both books represent an exodus from rural poverty and social and political confusion. ''Meridian'' also covers the civil rights movement, the Martin Luther King Jr. years, and the violence inflicted on civil rights workers with a vividness that few other writers have equaled. It also demonstrates the problems beyond racism and social ills that individuals must confront. In ''The Color Purple,'' two women survive separation and loss of children and family to discover that a loving relationship can exist between men and women. This novel provides both a peace and a conclusion to the conflicts Walker depicts in her earlier works, and here the racial aspect has been removed, leaving the black characters to confront one another. Walker has said that black women are more loyal to their men than to themselves, and her blacks are individuals. She never condescends to create them otherwise. Her characters exist in a thoroughly documented landscape , where they labor and survive despite their differences. Black men and women sharing a rural Southern heritage may recognize their own lives in Walker's fiction, as well as in her essays and lectures.

Walker's writings are engrossing reading, whether she writes on rural poverty , political commitment, the plight of the artist, personal relationships, or racism among feminists. She is a generous and intellectual writer, and her accounts and memories of friends and family are honest and engaging. There are other important black women writers, such as Gayl Jones, Toni Morrison, and Ann Petry, but Alice Walker is unlike any of them: She is her own woman. Zora Neale would have been proud.