The study of the flora in Malak Preslavets Swamp Protected Locality has established the existence of 177 higher flowering plants belonging to 61 families (List of Species). This fact means nothing in itself. Its importance can only be appreciated if the data is compared to analogous data about similar territory. This comparison is possible thanks to Tsonev’s study (2002) of the plant cover of Kalimok Protected Locality. He reports over 369 taxa of higher plants on a territory of 66,000 decares. It is immediately clear that the species identified in Malak Preslavets Swamp with an area of only 385 decares, i.e. 170 times smaller than that of Kalimok Protected Locality are only 2.5 times less. The comparison establishes significantly greater flora density in Malak Preslavets Protected Locality. This fact is evidence of the great phyto-diversity on this territory and hence its importance in the network of wet areas in Bulgaria. What is more, this protected locality is less affected by technological impacts, which makes it very suitable for conducting research on it.
In addition to the above higher plants, we can easily say that a more extended and thorough study of the flora of Malak Preslavets Swamp Protected Locality will increase their number by 15-20 species. The presence of Rootless Walter Meal (Wolfia arrhiza) – a protected species listed in the Bulgarian Red Data Book, the duckweed (Lemna gibba)- another protected species in the Bulgarian Red Data Book, the small pondweed (Potamogeton pussilus), the cowslip, the Cyclamen coum, etc. will almost certainly be established.
The white water lily (Nymphaea alba) is definitely the most important plant in the group – it is an endangered species in the Bulgarian Red Data Book.
Water lilies are perennial plants growing in water or swamp with large round leaves and big white flowers floating on the water surface. In May, the leaves emerge on the water surface and form large plantations. The water lily blossoms from June through September. This type forms almost clean colonies taking up about 46 decares of the swamp’s surface. That is why currently the white water lily habitats in the swamp form the biggest flowering population in Bulgaria.
Local people say that there used to be a large population of summer snowflake (Leucojum aestivum) growing in the swampier part of the tail of the protected locality. This plant is listed in the Bulgarian Red Data Book as an endangered species. The summer snowflake is used to make very important healing substances contained in many drugs. The artificial increase of the water level in the 1980s led to its extinction. There may be a summer snowflake here and there but they grow in suppression and develop only their vegetative organs, which makes them difficult to notice or find.
The edge parts of the swamp are grown with common reed (Phragmites astralis). Very often the reed forms clean spots, especially when these populations are near the bank. However, when reed cenoses are situated in the water, they are interspersed with: Lesser duckweed (Lemna minor), Sparganium ramosum, broadleaf cattail (Typha latifolia), narrow-leaf cattail (Typha angustifolia), European frog bit (Hydrocharis morsus-ranae), and towards the swamp’s tail you can spot Ivy leaf duckweed (Lemna trisulca) among the reed. ? As stated earlier, thanks to the geo-botanical division of the studied territory, plant cover in this part of the country has a definitely steppe-like nature. This nature is enhanced by the gallium (Galium humiffusum) and Jerusalem thorn (Paliurus spina-christi) among other plants found on the territory of the protected locality. Higher air humidity predisposes the presence of the raywood ash (Fraxinus oxycarpa) - a typical euxeinos element in the flora of this country.
During this investigation of the Malak Preslavets Protected Locality, on 28.03.2004, immediately next to the west bank, a higher aquatic plant was discovered and identified as Nuttall’s pondweed (Elodea nuttallii). This means that Malak Preslavets Protected Locality is the first inland water area in Bulgaria where this species has been found. We need to point out that Nuttall’s pondweed is a new species for Bulgarian flora, first discovered in the summer of 2003 in the aquatory of the Danube.
Among higher plants, the most numerous are The Compositae family (Asteraceae) represented by 21 species. Then come the Gramineae family (Poaceae) with 13 species and the Mint family (Lamiaceae) with 12 species. Then follow: The Legume family (Fabaceae) with 11 species, the Rose family (Rosaceaе) with 9 species and Umbelliferae (Apiaceae) with 7 species. It should be noted that within the whole protected locality, 2 families are represented by 5 species each, 1 family is represented by 4 species, 14 families are represented by 3 species each, 9 families - by 2 species and 27 families – by 1 species each. Most of them are weeds or ruderal plants - nettle, chicory (Cichorium intybus), Solanum nigrum, the various mulleins, etc. There are some species that are more or less artificially introduced - mulberry, hemp, amorpha, apple. We can conclude that the protected locality is rich in antropophytes, which is the result of the interaction with adjacent areas. One of the reasons for this active invasion of antropophytes is the proximity of the village of Malak Preslavets, whose arable land borders on the locality.