Nyananyo B. L. (1988): The systematic significance of seed morphology and anatomy in thePortulacaceae (Centrospermae).—Folia Geobot. Phytotax., Praha, 23: 275–279.—The seeds of 115 species in eighteen genera of the familyPortulacaceae were examined with the scanning electron microscope. Longitudinal sections of seeds of representatives of all the genera were examined with the light microscope. Two broad groups based on shape of the seeds, ornamentation of the external surface of their testa, and the position of the embryo relative to the endosperm were recognised. The first group comprising three genera:Anacampseros L.,GrahamiaGillies andTalinopsisA. Gray, have seeds which are pyriform with wings and trichomes, and an embryo that is more or less parallel to the endosperm, while the second of fifteen genera:Calandrinia H.B.K.,CalyptridiumNuttall,CalyptrothecaGilg,CerariaPearson etStephens,Claytonia L.,LenziaPhilippi,LewisiaPursh,LyalliaHooker fil.,Montia L.,Portulaca L.,PortulacariaJacquin,SilvaeaPhilippi,TalinellaBaillon,TalinumAdanson, andWangeriniaFranz, are reniform without wings and with an embryo that is horse-shoe shaped around the endosperm.