Rendijas by José María Lima (Cuadernos La Torre, Editorial de la Universidad de Puerto Rico, 2001). There is a preview available on Google books here.

José María Lima (1936-2009) was a poet, mathematician, painter, Marxist, activist and professor. The bulk of his work remained unpublished until the end of his life, when the University of Puerto Rico commissioned the selection and publication in 2001 of this book , Rendijas [roughly Slits or Cracks or Gaps]. His first poems were published in 1954 in a journal edited by Juan Ramon Jimenez. In the 60s he worked as a journalist for El Mundo, studied at Harvard and UC Berkeley, and became a political activist, travelling to Cuba in protest of the U.S. embargo. Returning to Puerto Rico to he was the subject of harassment and persecution from the UPE, a pro-statehood organization, for his political views. In the 70s he began teaching mathematics at the University of Puerto Rico in Rio Piedras where he stayed until he retired. His first book of poetry was Homenaje al ombligo, a collaborative project with his then-wife Angela Maria Davila in the 60s; his second, La sílaba en la piel was published in 1982. Rendijas was his third, most extensive, and final, publication.

His work has, as far as I can tell, never been translated into English. In fact, it seems as though before this volume, his work was not widely available in Puerto Rico, though it was (and is) widely respected. An inheritor of the Latin American avant-garde, he is considered, alongside Clemente Soto Vélez and Francisco Matos Paoli, an important innovative voice in the 20th century. He is the subject of a book-length critical study, Lógicas del extravío: Anatomía existencial en la poesía de José María Lima by Zoé Jiménez-Corretjer (Ediciones Puerto; 2010). To quote the blurb for Rendijas (in my translation): “From poems of war, to utopian aspirations, to the tender obsessive stanzas of his love poems, we find in Lima’s oeuvre the combination of social conscience and revolution, manifested in a refined and original language that represents a major break with the poetry of his time.”

The book is divided into six sections: 1. Hacia el olor del pan (poema de guerra) [Toward the smell of bread (war poem)]; 2. Viajes al interior (poemas personales) [Travel within (intimate poems)]; 3. Los óleos esenciales (arte amatoria) [Essential oils (art love)]; 4. Atrechos por el extravío (ARS) [Shortcuts for getting lost (ars)]; 5. Poemas de la muerte [Death poems]; 6. Penúltimos poemas [Penultimate poems]. Having merely skimmed sections of this book, I’m most immediately interested in the political poetry of the first section and the avant-garde poetry of the fourth section.

Biographical Sources:

http://ohdiosarantza.blogspot.com/2005/10/jos-mara-lima-ignoto.html

http://www.primerahora.com/lamentan_muerte_del_profesor_jose_maria_lima-293047.html