portlandia (rubiaceae) is a genus endemic to jamaica. the volatile organic constituents of p. albiflora, p. coccinea, p. grandiflora, p. latifolia and p. proctorii were analyzed by headspace solid-phase microextraction (spme) coupled with capillary mass spectrometry. the main constituents detected in these species are 1-penten-3-one, hexanal, (e)-2-hexenal, linalool, borneol and methyl salicylate. all species are rich in aliphatic aldehydes, mainly represented by (e)-2-hexenal, that range from 17% (p. latifolia) to 90% (p. coccinea) of total volatiles. the high content of aldehydes is characteristic to portlandia species and may serve as a chemical marker to differentiate portlandia from related genera within the rubiaceae.