Pteridophytes (ferns and fern allies) are spore-bearing, nonflowering, vascular cryptogamous plants. They comprise two independent phases in the life cycle. The gametophytic phase stays for a short period, whereas, the sporophytic phase is the dominant phase in the life cycle. The ferns are distinctive in the rhizome, frond, and sori, whereas the fern allies have small-scale-like leaves and strobilus. Pteridophytes preferably grow in moist, cool climatic conditions and predominantly in tropical rainforests. Their occurrence in dry deciduous to moist deciduous or miscellaneous tropical forests is also common. As per the recommendation of CBD and the priorities of NABP, the comprehension of regional floras has been the subject of present day’s priorities. In view of the above fact, an attempt has been made to prepare a checklist of ferns and fern allies of Uttar Pradesh. The total forest area constitutes about 6.88% of the total geographical area of the state, and the pteridophytes are one of the major components of the vegetation of Uttar Pradesh. The province is the 5th largest state of India in the area and covers an expanse of about 2,43,290 square kilometers. The province is situated between 23° 52′–31° 28′ N and 77° 3′–84° 39′ E and may be categorically divided, based on their remarkable geographical variations, into four regions. The mountainous Vindhya region in the south; the Gangetic plain in the central; the upper Gangetic plain, the Terai and the foothills region in northern Uttar Pradesh exhibit a variety of climatic conditions, soil composition, ecological niche, and annual rainfall (Singh et al. 2017). Due to varied geographical ranges and climatic conditions, the soil and land cover of the province comprises mainly three kinds of forests viz. tropical moist deciduous, tropical dry deciduous, and tropical thorn forests (Singh et al. 2017). It was observed that the above forests either primarily occur in the north or partially in the south regions of the state, however, due to excess agricultural practices the central region harbors poor forest.
In view of the unique habitats, ecology, and climatic conditions, there was a need to prepare a comprehensive checklist of the plant resources of Uttar Pradesh including the pteridophytes, and also investigate the extent of species composition in the three varied geographical regions. A comparative study on the species holding capacity of the three major geographical regions has revealed that a total of 36 species occur in the Terai regions, 29 in the Gangetic plains, and 26 in the Vindhya ranges. It was proposed that the maximum species representation from the Terai region was due to the prevalence of the humidity, wetland areas, and its proximity to the foothills. In contrast, the poorest records of fern allies and ferns in the Vindhya range were due to dry, low moisture, high temperature, and excessive habitat degradation by anthropogenic activities (Singh et al. 2017). The present checklist reports the enumeration of pteridophytes (fern allies and ferns) from this province providing information about the diversity, distribution pattern, locality of occurrence, habit, habitat, and their usefulness, if any. The present checklist comprehends 10 species of fern allies and 49 species of ferns belonging to 14 families and 4 subfamilies from the current geographical boundaries of Uttar Pradesh in India. The fern allies are traditionally divided into five families (Psilotaceae, Lycopodiaceae, Selaginellaceae, Equisetaceae, and Isoetaceae). The representatives of the fern allies in Uttar Pradesh belong to four families. Similarly, the fern representative belongs to 10 families and four subfamilies.
