By analysis of the flora elements of the wider area of Slavonian highlands, from geographical and plant point of view, this area proves to belong to the Euro Siberian - North American region with registered little less then 1500 species. The most represented flora elements are those from Europe and middle Europe, with important elements from South Europe and Mediterranean.
Flora system in Nature Park Papuk is rich and divers, what is the consequence of relief contrasts, diverse of geological structure, and diverse of pedological and climate influences.
Due to the exposure to the danger of extinction and disappearance of certain species, it is important to protect entire phytocenosis or entire eco system. Forming of botanic reservations can preserve ecological conditions where certain species can live and survive.
In the Nature Park Papuk the botanic richness is especially noticed in highlands of Pliš-Mališčak-Lapjak, in south parts of Papuk, Petrov vrh in Krndija, and peak of Papuk, with the most protected, endangered, sensitive and rare species.
Here are some examples of Papuk most interesting flora.

Winter Aconite
Eranthis hyemalis (L.) Salisb.
Family - R a n u n c u l a c e a e

Winter Aconite is a plant that lasts for several years. The stalk is upright, hollow, smooth, and green or dark brown, and it grows from a bulbous rootstalk. The ground leaves are on the long pedicle, they are round and heart shaped, divided like fingers on 5 to 7 segments, which have mostly deeper or shallow cuts, and they develop upon blooming. The flowers are separate, 2 to 3 cm in length, surrounded by the 3 more or less horizontally placed, leaves. The Winter Aconite grows in light and warm habitats, in light forest, edges of forest and bush wood, oak and hornbeam forest, orchards, meadows and cultivated lands.
The Winder Aconite is a rare plant, Tertiary relict, and the number of them is decreasing with deforestation and ploughing of meadows for cultivation. It is protected by the Law About Protection of Nature, dated June 10, 1958, in all its natural habitats.

Christmas Holly
Ilex aquifolium L.
Family - A q u i f o l i a c e a e

Christmas Holly is a small evergreen tree, or shrub, which can reach up to 10 m in height. The leaves are thick and lathery, with wavy edges and triangular spines or pointed prickles, dark green and shiny. The wave and spines of leaves changes, and can also disappear. The flowers are unisexual, have male and female flowers, they are small and collected into umbel inflorescence of a yellow colour, developed in leaf axils. The fruit is a bright red berry. The Christmas Holly can live up to 300 years. It grows in deeper, stirring soil, carbonate habitats of beech-tree, beech, and fir tree forests, and rarely in the mixed forests.
The Christmas Holly is a protected species. The number of them is lessening, mostly because of cutting it for decoration purposes. The species is protected by the Law about Protection of Nature, dated June 09, 1953.

English Yew
Taxus baccata L.
Family - T a x a c e a e

English Yew is an evergreen bush, or small tree of broad and a round crown. It grows slowly, and can reach up to 15 m in height, with the trunk of 1 m in diameter. The leaves are dark green and smooth on the top, and on the bottom have two light green lines. They are mostly comb-like divided, and are renewing each 4 to 5 years. The male flowers appear in the fall, and look like yellow head-like formation. The female flowers appear in the spring, separately and covered with scales. The product is a dark brown, egg like seed covered with succulent cover, which is in the beginning green, and later of a red colour. All parts of English Yew, except for product, are poisonous, especially the pines, because of alkaloid 'taksin' which the plant contains. The plant reaches maturity when is about 30 years of age, and can live over 1000 years. It grows in the beech-tree, and fir and beech tree forests, usually in shadow, but it also grows in the open spaces.
Their number is decreasing, because of deforestation of a quality tree, while growing is very slow. The English Yew is protected by the Law about Protection of Nature, dated May 09, 1969, in all habitats.

Spurge Laurel
Daphne laureola L.
Family - T h y m e l a e a c e a e

This is the woody evergreen bush, whose height reaches from 40 to 120 cm, and it is slightly dendriformed. The leaves are oblong and halberd shaped, lathery, naked with certain glow, and spirally situated on the steam. The flowers are gathered into hanging racemose inflorescence of a green or green-yellow colour. This plant grows in the homophile beech tree forests in highland areas, partially covering thermopile forests on the loose, fresh and rich soils on carbon base. The Spurge Laurel is a rare species, and its number is lessening because of cutting for decorative purposes, and because of destroying its habitats by deforestation
It is protected by the Law about Protection of Nature, dated April 16, 1952, in all natural habitats.

Iris
Iris graminea L.
Family - I r i d a c e a

Iris has a short and thin rootstalk. The stalk is slender, with two edges and about 15 to 35 cm tall. The leaves are linear and long like grass leaves, wide up to 1 cm, and go well above the stalk. The flowers are hermaphrodite, 1 to 2 on each stalk and are of purple colour, with darker thin veins and longitudinal stripes, and are of very pleasant smell. This Iris grows in thermopile forests and bushes on more or less humus, sandy, or gravel habitats, in low laying and hill areas.
In Croatian flora, Iris can be found in forests and hills with bushes in highlands and bottom of the mountains. The number of Irises is decreasing due to the picking for decorative purposes.

Willow Gentian
Gentiana asclepiadea L.
Family - G e n t i a n a c e a e

Willow Gentian is a several years lasting plant, heights between 20 and 60 cm, or more. From the rootstalk, more then one stalks appears which are upstanding or slightly inclined. The leaves are numerous, sitting, at the bottom rounded, otherwise halberd shape and tapered to a point. There is no bottom rosette. The flowers are separate, or 2 to 3 together in a leaf axils. The flower calyx and crown are bell-shaped with triangle and pointed top. They are rather large (5,5 cm) of a dark azure colour, sometimes light blue or purple, rarely white. Inside the flowers are red-purple spots and light longitudinal stripes. It blooms from July till September. It grows in the forest on the hills or bottom of the mountains, edges of forests, meadows, and forest meadows, on moisture habitats.
The plant grows separately or in smaller clods, and the number is decreasing due to changes of ecological conditions and picking.