There are 89 islands, islets and reefs in the Kornati National Park. The great number of islands, their different geomorphological characteristics, their shapes, climate conditions, cliffs (crowns) on the outer island chain, all of that makes the islands special and it's visible in their flora and vegetation.
This specialness was influenced by various factors closer or farther in the geological past, shaping into an extremely interesting and unique place.
In the view of natural sciences, particularly biogeography, the Kornati islands belong to a separate Adriatic vegetational sector of the Mediterranean region. An important feature of the sector is a mutual association of plants belonging to the east and west Mediterranean floral elements. This is the place where the western, that is, eastern borders of their respective areas meet. The islands have a general Mediterranean plant cover with particular endemic plants, while in the vegetational and phytogeographical regards they belong to the eumediterranean holm oak zone.
The Kornati used to be covered with holm oak forests that people by their activities (like elsewhere in the Mediterranean) gradually turned into karst pastures.
Today's vegetation could be sorted into twenty plant communities with some of them represented only in fragments. Among the more important communities are:
- Fissure vegetation (chasmophyte vegetation) - the Phagnalo-Centaureetum ragusinae community on the limestone rocks of the eumediterranean vegetative belt. The characteristic species is Dubrovnik Knapweed (Centaurea ragusina), an Illyrian-Adriatic endemic species. The habitat of Dubrovnik Knapweed are the cracks and crevices of vertical carbonate rocks (cliffs on the outer islands). This community is comparatively poor in species because of the extreme ecological conditions (exposure to salinisation, sun, strong winds). It is also one of the communities peculiar to the Kornati.
- Vegetation of limestone coastal cliffs (halophile vegetation) - the community of rock plantain and sea lavender (Plantagini-Limonietum cancellati) with Rock Plantain (Plantago holosteum) and Eastern Sea Lavender (Limonium cancellatum) as the characteristic species.
- Tree Spurge stand (Euphorbia dendroides). This species makes up a separate community Oleo-Euphorbietum dendroidis both here and throughout the Mediterranean. It keeps in strictly specific ecological conditions (heat and aridity). An interesting feature of Tree Spurge is that it has an "African mentality". It sprouts leaves and blooms in autumn and winter, discards the leaves in late spring, and is almost completely bare during the summer. Such behaviour is characteristic for some plants in North Africa, where the drought – not the cold – stops the vegetation.
- Forest community of myrtle and holm oak (Myrto-Quercetum ilicis) with all its degradative stages.
- Ruderal nitrophyle pasture community of golden thistle and horehound with bunch grass (Scolymo-Marrubietum incani-brachypodietosum ramosi) This community appears in overgrazed locales. It is dominated mostly by spiny species.
Maybe we should pay more attention to the vegetation of karst pastures, as the most widely spread on the Kornati, particularly on the island of Kornat. For this eumediterranean area, it is important that its heavily degraded surfaces get overgrown with the karst pasture vegetation with submediterranean features. Most of the degraded surfaces are occupied by two communities. One of them is the community of feather grass and sage with kneeholm and bunch grass (Stipo-salvietum officinalis brachypodietosum ramosi) – it appears in comparatively heavily degraded limestone stony ground with shallow soil exposed to the wind. The other community, fescue and hairgrass with bunch grass (Festuco koelerietum splendentis brachypodietosum ramosi) – it appears on surfaces comparatively less heavily degraded than in the previous community.
Both communities with their characteristic species developed in large areas that served or serve as pastures. The two communities are exactly those that appear as "bare" ground during summer and appear lifeless to a cursory glance. They were created as the last stage in the process of degradation of forest vegetation. On the other hand, it is obvious that the karst pastures, as a characteristic feature of the karst landscape, are "under attack" by the pioneering vegetation of garrigue and macchia.
Although the flora of the Kornati National Park has been studied for two hundred years, it is still not completely known. The most studied vascular plants (ferns and spermatophytes) number around 650 species.
More important – if we can say that a species is more important or less important because every species has its place – plant species of this area are Dubrovnik Knapweed (Centaurea ragusina), White Corydalis (Corydalis acaulis), Felt Seseli (Seseli tomentosum), Adriatic Iris (Iris adriatica), Illyrian Iris (Iris illyrica), Silverbush (Convolvulus cneorum), Bunch-flowered Narcissus (Narcissus tazetta), Tree Spurge (Euphorbia dendroides), different species of orchids (Orchidaceae) and many others.