This elegant 1975 semi-postal issue from Luxembourg highlights native orchid species as part of the annual Caritas charity series. The set features finely illustrated botanical studies: Anacamptis pyramidalis (Pyramidal Orchid) and Epipactis palustris (Marsh Helleborine), rendered in soft natural tones. Issued with surtax values (3F + 25c and 4F + 50c), proceeds supported social welfare initiatives. Printed by Courvoisier S.A., these stamps are admired for their delicate engraving and balanced composition. A beautiful thematic addition for collectors of flora, orchids, and charity issues.