The flora of Krka National Park

Thanks to geographic position and the large number of different habitat types, the plant life around the Krka River is exceptionally diverse and picturesque, with 1186 species recoreded to date.

The course of the Krka River lies in the transition zone between the evergreen Mediterranean and deciduous sub-Mediterranean vegetation belts. The natural forest vegetation has been significantly altered due by anthropogenic activities. Nonetheless, the plant life around the Krka River is exceptionally diverse, with 1186 species recorded, thus attracting both scientists and visitors.

Geographic position and the large number of different habitat types (travertine barriers, aquatic habitats with flowing and standing waters, cliffs, rocky terrain, anthropogenic habitats), the plant life around the Krka River is exceptionally diverse and picturesque, with 1186 species recorded to date.

The Krka River basin is dominated by white hornbeam forests and thickets, macchia, garrigues, grasslands, rocky pastures, weedy and ruderal communities, and planted conifer stands. Even today, primary vegetation types can be seen along the Krka and Čikola Rivers, such as the flora of the aquatic and wetland habitats, and the canyon vegetation. The most abundant species are the Mediterranean and southern European plants, though there are also many central European, European, and Eurasian floral elements, in addition to American, subtropical and tropical species.

The chimney bellflower is an Adriatic/Illyrian endemic species. It is found throughout the entire area of Krka National Park.

The chimney bellflower (Campanula pyramidalis) is an Adriatic/Illyrian endemic species. It grows on caves, in rock crevices and walls in the coastal regions, and can be found at altitudes of up to 1000 m on Mt. Velebit. The chimney bellflower is found throughout Krka National Park, growing on rock crevices and stone walls, on rocky slopes and rocky pastures and open areas with deciduous thickets. This is a biennial or triennial plant that can grow up to 150 cm high. The stem is vertical, strong and simple, or can be branching, like a broom, bare and blunted. The leaves are bare. At the base of the plant, the leaves are on long stems and are broad and ovate, with a blunted tip and roughly serrated edges. Leaves on the plant stem are on shorter stems, are egg-shaped or spear-shaped, with a heart-shaped base and serrated edges. The flowers are on short stalks, usually in clusters of three, at the bases of the upper leaves, clustered together in an upright, pyramidal raceme. The flower is widely bell-shaped, with a diameter of 3 cm, with triangular lobes cutting almost halfway down the entire length of the flower. The colour is light purple to blue. Blossoms in July and August.

Grassy bells is a plant that is endemic to the coastal areas of the Dinaric mountain range, and grows on rocky and sunny grasslands from the coast to high altitudes.

In Krka National Park, we find the plant grassy bells (Edraianthus tenuifolius) on the rocky pastures at Žurića brdo and Roški slap. This is a low-growing perennial plant (height up to 15 cm), with tufts of densely hairy stems growing along the ground. The leaves are narrow and linear, and hairy along the edges. Leaves are 8 to 12 cm long, and about 1.5 mm wide. Bell-like flowers grow at the end of the stems, with several flowers aggregated in a cluster, surrounded by leaves that are wide and heart-shaped at the base, and narrow and pointy at the tip. The flower is a dark purple colour and blossoms in June and July. The fruit is a capsule with numerous seeds.

The scorpion senna is a widely distributed deciduous plant that grows up to 1 m in height.

The scorpion senna (Coronilla emerus subsp. emeroides) is widely distributed in Croatia. In Krka National Park, it can be found in the deciduous forests and thickets, macchia, on the rocky pastures and on rocks. In young plants, the branches are thin but strong, with a smooth, green skin which becomes greyish-green in older plants.

Leaves are unevenly stipulate, made up of 7 to 9 egg-shaped, bare leaves that are light green in colour, and 1–2 cm long. The blossoms are yellow, with 5 to 7 clustered together into a tight spike, on a common stalk about 2 cm long. The calyx is olive green with small serrated edges. The banner petal is an upside down egg shape, and often has some red colouring. The keel petals are bent upwards, with a long beak. 

This plant flowers in May and June. The fruit is a chambered legume that does not open.

The forests along the Krka River do not cover large areas of land, but they are of great importance for the overall landscape experience in an area of such contrasts between the rough karst, river and the sea.

Three forest communities dominate: mixed forests of holm oak and flowering ash (Orno-Quercetum ilicis), mixed forests of downy oak and white hornbeam (Querco-Carpinetum orientalis), and black hornbeam forests with autumn moor grass (Seslerio-Ostryetum). Due to centuries of exploitation, the downy oak and white hornbeam forests are now rare, and are most commonly found only in the form of low forests and thickets.

The forest community of holm oak and flowering ash is developed on the steep, sunny slopes, while the black hornbeam forests with autumn moorgrass are common on the shady slopes, and both are typical of the Croatian coastal areas. In addition to these forests communities, in the early 20th century, a large area around Skradinski buk was planted with Aleppo pine (Pinus halepensis) and black pine (Pinus nigra). Upstream to Roški slap, floodplain forests and thickets are common along the river's edge, dominated by willows (Salix alba, S. cinerea, S. fragilis, S. purpurea), black alder (Alnus glutinosa), black and white poplars (Populus nigra and P. alba) and narrow-leaf ash (Fraxinus angustifolia).

Low open thickets and/or dry rocky grasslands have developed in cut areas with degraded forests.

Thickets are primarily communities of Christ's thorn (Paliuretum spinae-christi) that are characterised by the spiny plant Christ's thorn (Paliurus spina-christi), red-berried juniper (Juniperus oxycedrus), terebinth pistache (Pistacia terebinthus) and osyris (Osyris alba). Two plant communities are commonly developed on the rocky grasslands that are used as pasturelands: pastures of koeleria and Illyrian fescue (Koelerio-Festucetum illyricae) in areas with more fine soil, and the rocky communities of feather grass and medicinal sage are common in limestone cracks and valleys with fine soil.

Along the banks of the Krka River, there are many small areas with humid and wetland grasslands (mowed meadows), exceptionally picturesque coastal meadows of the community clover and meadow barley (order Trifolio-Hordeetalia), which includes white clover (Trifolium repens), forest bluegrass (Poa sylvicola), buttercups (Ranunculus repens, R. acris, R. sardous, R. neapolitanus), summer snowflake (Leucojum aestivum), lax-flowered orchid (Orchis laxiflora), distant sedge (Carex distans) and hairy sedge (Carex hirta), along with two Illyrian/Adriatic endemic plant species, the meadow squill (Scilla litardierei) and Peucedanum coriaceum subsp. pospichalii.

On the low, silty banks of Visovac Lake, the Ćulišić ponds and the mouth of the Čikola River, the vegetation of true wetland habitats, such as tall reeds and cattails, is well developed.

On the river banks, the community of sedge beds (Cladietum marisci, Mariscetum) is dominant, and associated with stands of galengale (Cyperus longus) and marsh pennywort (Hydrocotyle vulgaris). Reed communities with club-brush (Scirpo-Phragmitetum mediterraneum) dominate where the water typically does not dry out, even in the driest periods, but remains on the soil surface. These communities consist of common reeds (Phragmites australis), great bulrush (Scirpus lacustris), narrow-leaf cattail and reedmace (Typha angustifolia and T. latifolia), yellow iris (Iris pseudacorus) and American water plaintain (Alisma plantago-aquatica).

Behind the reed belts, in somewhat deeper and slower flowing or standing water, are the aquatic plants. The most evident is the Myriophyllo-Nupharetum community, consisting of the white water lily (Nymphaea alba), European cow lily (Nuphar luteum), whorled and spiked water milfoil (Myriophyllum verticillatum and M. spicatum), mare's tail (Hippuris vulgaris), water starwort (Callitriche polymorpha), water knotgrass (Polygonum amphibium), and three-leaved water crowfoot (Ranunculus trichophyllus).

A special feature of the flora of the natural park are the communities of the fissures in the steep limestone cliffs in the Krka and Čikola River canyons, which include many rare and/or endemic plants.

Upstream from Roški slap, we find the community Moltkio-Campanuletum lepidae, composed of the Dalmatian endemic stone bellflower (Campanula lepida) and several Illyrian/Adriatic endemics: chimney bellflower (Campanula pyramidalis), mullein inula (Inula verbascifolia), Dalmatian pellitory (Tanacetum cinerarifolium), Illyrian iris (Iris illyrica), autumn crocus (Colchicum visianii), Adriatic violet (Viola adriatica), alyssum (Alyssoides sinuata), chervil (Chaerophyllum coloratum) and wolfen spurge (Euphorbia wulfenii). This community also often contains the maidenhair spleenwort (Asplenium trichomanes), scale fern (Ceterach officinarum), wall pellitory (Parietaria vulgaris) and common brighteyes (Reichardia picroides). Tufts of the endemic species rock moltkie (Moltkea petraea) are prominent on the rock cliffs in the Čikola canyon.

In the humid and shady travertine half-caves on the Krka River waterfalls, the moss community Eucladio-Adianthetum dominates, consisting of the lovely species southern maidenhair (Adiantum capillus-veneris).