Issued in 1967 under Spanish administration, this Pro-Infancia semi-postal stamp from Río Muni features a striking botanical illustration of slender green leaves set against a vivid pink background. The series supported child welfare programs (“Pro-Infancia”) while showcasing native tropical flora. The elegant plant depiction reflects the region’s lush biodiversity, and the fine engraving by F.N.M.T. (Fábrica Nacional de Moneda y Timbre) exemplifies Spain’s mid-century colonial-era design precision. Denominated at 40 céntimos, this issue is a beautiful example of Rio Muni’s brief but distinct philatelic history.