Both Jean Valentine and Alice Oswald have been called “mystical”; Valentine is a National Book Award-winning American “minimalist” and Oswald is among Britain’s leading new poets and a master of, among other things, a lanky polyvocal line.

Spacecraft Voyager 1: Selected and New Poems (Graywolf, 120 pages $15 paperback) is Oswald’s first US appearance. She trained as a classicist and worked for years as a gardener; this book is drawn from three previous volumes and new poems. Her most famous poem is “Dart,” a book-length meditation threaded with voices from interviews of people who live and work on the Dart River in Devon; it won the T.S. Eliot prize in 2007.

Oswald’s authority shines in these lines from “Ballad of a Shadow”: Take from me my voice and I shall voiceless go / to find you; take from me my face, / I’ll trek the hills invisibly, / my strength, and I shall run but keep no pace. The poem concludes: And when at last my love is understood, / with you I shall not love but breathe / and turn by breathing into flesh and blood.

The authority is not simply in Oswald’s renewal of an old sound but in the turning of the syntax into passionate response. The identity of the “you” remains a mystery but not the emergence of the incarnate meaning. This book throws down a challenge to American poets: the ecology of the spirit.

Oswald will be new to most readers, Valentine familiar — but familiar sounds funny in the context of her new book Little Boat (Wesleyan, 67 pages, $22.95). Where Oswald sweeps the reader into her river of words, Valentine deftly, almost silently, enters one’s consciousness and fills it with a tender spare music of profound resonance. The material is intimate and breathtaking but through her exquisitely disciplined art also transparent and tonic.

In Valentine’s hands, the unavoidable subject matter of aging —“Strange Lights,” a hospital sequence, is a triumph of art and spirit — becomes the occasion for gratitude. Valentine is a master composer capable of finding the symmetries and proportions in the most fugitive of experiences (the analogy with Bach is appropriate). What should be fragmented is monumental, whole. Here is “The Look”:

Pain took me, but / not woke me — no, / years later, your / look / woke me: / each shade & light: // to earth-love then / I came, / the first / beach grasses.