The Klokočka NNM was declared in 1956 on an area of 2.37 ha to protect a locality where the Siberian leopard plant (Ligularia sibirica) occurs. The national nature monument is also a part of the Niva Bělé u Klokočky Site of Community Importance.
The protected area lies in the Středočeský kraj – Central Bohemian Region between the town of Bělá pod Bezdězem and the village of Velký Rečkov at elevations of around 222m above sea level. The geological basement is Cretaceous sandstones of the Jizera Strata, on which we can find water-filled floodplain sediments with a predominance of sandy elements. The majority of the protected area lies on the alluvial plain of the waterlogged character of the locality, the soil profile includes Organic soil, Gley and Fluvisol.
Almost all of the territory, except for the fringe areas, is covered by a mosaic of wetland biotopes – alder stands, reedbeds, sedge growths and fenland vegetation. The alder carrs are dominated by alder (Alnus glutinosa) and such wetland forests (Carici acutformis-Alnetum) cover more than half of the protected area. The herb layer under the alders does not display a high species diversity and tall sedges, such as lesser pond sedge (Carex acutiformis), slender tufted-sedge (Carex gracilis) and bladder sedge (Carex vesicaria) dominate the undergrowth and are complemented by a few other species including green figwort (Srophularia umbrosa), marsh horsetail (Equisetum palustre), and the marsh fern (Thelyoteris palustris) which grows abundantly in alder carrs and reedbeds. The skullcap (Scutellaria galericulata) and the marsh cinquefoil (Comarum palustre) also grow here. Ruderal species also grow here as a result of pollution from the Bělá stream. We can also find typical stream vegetation along the Bělá with the hybrid water-cress (Nasturcium x sterile) and lesser water parsnip (Berula erecta).
Another common vegetation type is the vegetation of tall sedges (Magnocaricion), which has developed in places with permanently stagnating water, and includes an abundance of greater tussock sedge (Carex paniculata) and more rarely fibrous tussock sedge (Carex appropinqua), lesser pond sedge (Carex acutiformis) and hop sedge (Carex pseudocyperus).
The most valuable part of the monument is the fen meadow with the occurrence of the orchids – broad-leaved marsh orchid (Dactylorhiza majalis), marsh helleborine (Epipactis palustris) and common twayblade (Listera ovata). Other rare plants which grow on this meadow include marsh valerian (Valeriana dioica), broad-leaved cotton-grass (Eriophorum latifolium), round-headed rampion (Phyteuma orbiculare), bogbean (Menyanthes trifoliate), grass of Parnassus (Parnassia palustris), blunt-flowered rush (Juncus subnodulosus) and hard rush (Juncus inflexus). The most significant plant is the Siberian leopard plant (Ligularia sibirica), which grows on the forest-free fen but also in the open alder stands and fringe communities of sparse reedbeds. This rare plant remains sterile if it is shaded. Siberian leopard plants flower in late summer and their seeds ripen in September. Their presence is regarded as a relict occurrence of their much wider distribution in the early Postglacial period. The edge of the floodplain is dominated by moor-grass (Molinion), whereas wood small-reed (Calamagrostis epigeios) is spreading over drier areas.
Strong populations of the tiny mollusc – Desmoulin’s whorl snail (Vertigo moulinsiana) and the snail Perpolita petronella live at Klokočka NNM, and like the Siberian leopard plant these gastropods are regarded as relicts. The whirlpool ramshorn snail (Anisus vortex) and the tiny freshwater snail Valvata cristata have also been recorded here. Typical spider species include the wolf spider Hygrolycosa rubrofascidata, the dwarf spiders Aphileta misera and Taranuctus setosus and the jumping spider Marpissa radiate. Birds which can be seen in these wetlands include the river warbler (Locustella fluvatilis) and the tree pipit (Anthus trivialis). Goshawks (Accipiter gentilis) nest in the surroundings.