The genus Hymenonema is the only Greek endemic genus comprising two representatives, namely H. graecum and H. laconicum. The former is an endemic species occurring in the phytogeographical regions of the Cyclades and Kriti-Karpathos. Hymenonema graecum probably emerged via allopatric speciation during the Pliocene/Pleistocene boundary. It grows on limestone, granite or schists, up to 450 m a.s.l.
Helichrysum amorginum is a narrow endemic of the Amorgos’ archipelago, first described by Orphanides in the mid-19th century. It grows on calcareous crevices and cliffs. Its inflorescence is a (sub-)globose capitula, bearing distinctive white to whitish or whitish-pink bracts. The Chozoviotissa monastery in Amorgos – one of the most significant Aegean refugia, as it hosts several narrow and rare endemic taxa – is the species’ locus classicus.
Campanula laciniata is a palaeoendemic perennial chasmophyte, with a disjunct and fragmented distribution, occurring in the phytogeographical regions of the Cyclades and Kriti-Karpathos. It usually grows on precipitous, often inaccessible, calcareous cliffs, it has large, showy flowers and often comprises small and scattered populations.
Saponaria jagelii is a Greek narrow endemic, occurring only at two sites in W Elafonisos. It has been reported, but not recorded from the Malea peninsula. It flowers from late March to early May, while its fruiting period lasts from early May to early June. It grows exclusively on sandy beaches (dunes) and is part of the characteristic plant communities formed in disturbed sites along sandy beaches.
Polygala helenae is a Greek single island endemic, known only from two sites near Kalamos in Kythira. It flowers mainly in April at low altitudes, in phrygana and on sandy soil. Polygala helenae was assessed as a Vulnerable taxon in the first edition of the Red Data Book of the Rare and Threatened Plants of Greece, due to its restricted distribution and its small population. At that time no major threats were detected that might affect the species’ survival.