1. INTRODUCTION
Pteridophytes are one of the neglected plant groups that form a prominent part of the earth’s vegetation. They create a connecting link between non-vascular lower group plants and the higher group seed-bearing plants. Members of the group have immense economic and ecological significance. Although 250 million years ago pteridophytes constituted the majority of the flora of the planet, thereafter they were mostly left behind by seed-bearing plants [1]. Pteridophytes, comprising Polypodiopsida and Lycopodiopsida (including Selaginella), are the second most extensive assemblage of vascular plants, encompassing over 11,916 documented species that belong to 337 genera under 51 families and 14 orders [2]. While their typical distribution is in damp, shady environments like the understory of rainforests, certain species also inhabit rocky terrains and grow as epiphytes in the canopies of forests. As pteridophytes are so sensitive to changes in environmental factors like humidity and sunshine intensity, they may serve as signs of climatic change and other environmental disturbances [3]. They are important contributors to several biodiversity-rich regions. To gain a deeper comprehension of any ecosystem, it is crucial to examine the phytosociological characteristics and diversity patterns of each community within these ecological settings [4]. The habitat of numerous pteridophytic species in several conserved areas and biodiversity regions was destroyed by anthropogenic activities. Furthermore, infrastructure building, road expansion, and tourism have been observed to negatively impact these populations. In the few decades, many researchers have set their goal in this direction and conducted many phyto-sociological and ecological surveys in forests and biodiversity regions. Regular and systematic documentation of any plant group is required to evaluate its status. The pteridophytes are a paraphyletic group of plants consisting of six extant classes, viz., Lycopsida, Equisetopsida, Psilotopsida, Ophioglossopsida, Marattiopsida, and Filicopsida [5-7] or four extant classes, viz., Psilotatae, Lycopodiatae, Equisetatae, and Filicatae [8]. During the last few decades, the conception of studies on pteridophytes has undergone incredible innovation in comparison to any other group of plants. Many new species and taxa have been reported during the last few decades from several regions [9-14] of the globe. Like most of the biodiversity-rich regions, the Indian subcontinent was also explored by several workers in the context of pteridophytic flora. Some of these are: A Handbook to the Ferns of British India, Ceylon, and the Malay Peninsula [15], The Ferns of Bombay [16], and a Census of the Indian Pteridophytes [17]. Pteridophyte flora of the Western Ghats–South India [18], Companion to a Census of Indian Pteridophytes [19]. An illustrated Fern Flora of West Himalaya [20], Taxonomic Revision of Three Hundred Indian Sub-continental Pteridophytes [21], A Summary of the Status of Threatened Pteridophytes of India [22], Fern and Fern-Allies of Nepal, and Satara District. Maharastra [23-25], Annotated Checklist of Indian Pteridophytes parts I, II, and III [26-28]. Some of the researchers prefer the documentation of a region-based or district-based checklist of respective plant groups for a better understanding of their ecological and taxonomical situation.
District Jalpaiguri is one of the biodiversity-rich regions that is situated in the northern part of the Indian state of West Bengal [29]. The district of Jalpaiguri, depicted in Figure 1, is located between latitudes 26º15′47″ and 26º59′34″ N, and longitudes 88º23′2″ and 89º7′30″ E. It encompasses altitudinal ranges ranging from 100 ft to 3000 ft above sea level, with an average rainfall of 3000 mm per year. It shares international borders with Bhutan and Bangladesh in the north and south respectively, and borders with Darjeeling Hills in the west and northwest; Alipurduar district and Cooch Behar district on the east [30-33]. Phytogeographically, it is located at the foothills of Eastern Himalaya and shares a diverse habitat, including forest patches and riverine zones [34]. Although Teesta, Mahananda, and Jaldhaka are the three main rivers of the district Jalpaiguri but several tributaries (Chel, Ghees, Dharala, Karola, Mal, Duduwa, Kartowa, Panga, etc.) of the three rivers thoroughly dissected the district topography. India possesses a diverse and abundant collection of pteridophytic plants, which can be attributed to its origin in Gondwanaland and subsequent movement from the southern hemisphere toward Eurasia [35]. This migration brought with it the ancestors of today’s pteridophytes from regions such as Australia, Africa, and Madagascar, as well as potentially unique species that are native to India. That is why several workers have conducted taxonomic enumeration of pteridophytes in several districts of India, especially in the districts that are close to the Himalayan Mountain range [36-42]. As the district Jalpaiguri is in the foothills of range, it has gained much attention from several researchers. Among the 23 districts of West Bengal, the pteridophyte flora of some districts, like Darjeeling [43], Nadia [44], Birbhum [45], Howrah [46], Burdwan [47], Hooghly [48], Sundarban [49], Purulia [50], Coochbehar [51,52] was well documented. Though some workers have surveyed some parts of Jalpaiguri [53-55], there is still lack of comprehensive study on pteridophyte flora in the district. In addition, the nomenclature of the ferns has changed significantly in recent times. Therefore, to provide an updated and more or less complete list of ferns in the district, the present work has been undertaken. Due to the lack of adequate information, there is a need for study and documentation on the distribution, floristics, and diversity of pteridophytes in this district. This is relevant because of the ecological and ethnobotanical value of these plants in the region. Therefore, an initiative was set up to describe and conserve the ferns and fern allies in this area.
2. MATERIALS AND METHODS
Pteridophyte specimens were procured from nine blocks within the districts. The vegetation survey was conducted from January 2019 to January 2024. Some excursions were conducted in the blocks of the district during this period. Fresh specimen collections have been conducted from various locations, encompassing all nine blocks inside the aforementioned district of the state of West Bengal. A wide range of pteridophytes, encompassing those that thrive on terrestrial surfaces, rocky surfaces, plant bodies and aquatic environments, have been recorded. The diagnostic characteristics of all the specimens were examined, and detailed field notes were recorded on fresh plant materials. Accurate photographs were captured for each of the species. Field notes were taken, including ecological data, habit, habitat, and diagnostic features of each species. Specimens were identified via taxonomic keys as well as descriptions from taxonomic literature and Pteridophyte flora [26-28, 56-74] and compared with digital images of vouchers and type-specimens deposited in various herbaria. Several experts were also consulted. The collected specimens have been deposited in the Botanical Survey of India (BSI) Arunachal Pradesh Regional Centre (ARUN!) and Herbarium (Dept. of Life Science), Govt. Model School, Mal (GMSMH), Jalpaiguri. GeoCAT [75] is also used to help assess the Extent of Occurrence (EOO) and the Area of Occupancy (AOO) of the collected taxa in Jalpaiguri, West Bengal (India).
3. SYSTEMATIC TREATMENT KEY TO FAMILIES
A. Leaves simple; veins unbranched………………………… B
A. Leaves complex; veins branched……………………….,... D
B. Leaves in whorls, forming sheath at nodes; stem hollow and grooved ....................................3. Equisetaceae
B. Leaves spirally arranged without forming whorls; stem solid and smooth ............................................ C
C. Plants heterosporous…………………………..2. Selaginellaceae
C. Plants homosporous ………………………..1. Lycopodiaceae
D. Fronds usually have indefinite growth due to the presence of dormant vegetative buds on the main rachis ...............................................8. Gleicheniaceae
D. Fronds 100–200 cm long, dichotomously pinnate; pinnae palmately lobed; sori arranged on finger like projections on lamina margin ...............................6. Lygodiaceae
E. Spikes are simple and solitary ........................4. Ophioglossaceae
E. Spikes are not simple but branched ..................................... F
F. Plant epiphytes; lamina simple .............................14.Vittariaceae
F. Plants terrestrial; lamina one or more pinnate ..................... G
G. Indusium bilipped, marginal ................................................ H
G. Indusium can be cup-shaped arises around the base of the sorus, leaves large, up to 5 m spores tetrahedral .............................................10. Cyatheaceae
H. Frond large, thick; sori terminal or submarginal, falsely indusiate or indusiate; indusium not tubular or bilipped ............................................................... I
H. Fronds pinnate or bipinnate, glabrous; indusia single .................................................13. Pteridaceae
I. Rhizome non-tuberous ...................................... JI. Rhizome hairy or scaly or fibrillose ....................................K
J. Rhizome scaly or fibrillose; veins free, but vein ends tend to anastomose .................................21. Lindsaeaceae
J. Rhizome hairy; veins free or reticulate; sori submarginal at vein ends .....................11. Dennstaedtiaceae
K. Lamina pinnately decompound, finely dissected; sori terminal on veins or submarginal ..................................................20. Davalliaceae
K. Lamina simple, lanceolate, margin entire; sori close to midrib to form a row on either side close to costae .......................................19. Oleandraceae
L. Plants are usually epiphytes or lithophytes; sori exindusiate but are protected by paraphyses ................... M
L. Plants terrestrial; sori protected by an indusium, rarely exindusiate ................................................................... N
M. Stipes articulate to a short phyllopodium .......9. Polypodiaceae
M. Stipes generally scaly and fibrillose; lamina glabrous or scaly or fibrillose; rachis prominently grooved ......................................................18. Dryopteridaceae
N. Sori elongated, either discrete or forming continuous coenosori on a secondary vein, close and parallel to the costa or costule, superficial or sunken; indusia flap-like ..............21. Blechnaceae
N. Sori not forming coenosori, superficial; indusial shape like the sori ..................................................... P
P. Stipes, rachis, and lamina are generally hairy; hairs are uniseriate, unicellular, or septate, multiseriate hairs are absent; scales have unicellular hairs on the surface or margin ...............16. Thelypteridaceae
P. Stipe, rachis, and hairy but also with multiseriate fibrils or scales glabrous ........................................................ Q
Q. Rhizome scales clathrate; sori generally on one side of vein ..................................................15. Aspleniaceae
Q. Rhizome scales non-clathrate; sori generally on both sides of vein .............................................................. R
R. Sori sessile ............................................................................. S S. Sori round; indusial globose .........................17. Woodsiaceae
S. Sori linear along veins and eventually acrostichoid ........................................................5. Marattiaceae
T. Plants are natant or floating .................................................... U
T. Plants are rooted within aquatic body .................7. Marsileaceae
U. Three leaves in a whorl on a rootless rhizome ...............................................................23. Salviniaceae
U. Two rows of bilobed leaves on a root-bearing rhizome ................................................................22. Azollaceae
4. RESULTS AND DISCUSSION
The current effort is the result of a five-year-long, comprehensive field study conducted throughout the area. The current study reported the presence of 86 species of pteridophytes (Plates 1-7) from 23 families [Figure 2]. Among the collected species, 19 belong to Pteridaceae, while 12 belong to Polypodiaceae. Due to the extensive range of soil and climate variations, as well as the diverse range of habitats such as rivers, swamps, forests, cultivated fields, orchards, meadows, etc., a wide variety of land plants. Among the studied species, 40 were terrestrial, 18 species were lithophytic, 19 species were epiphytic, and 9 species were aquatic [Figure 3]. Epiphytic ferns, or fern-allies grow on the base platforms of several trees. Some common tree species that serve as hosts for pteridophytes include Alstonia scholaris R. Br., Shorea robusta Gaertn., Lagerstromia speciosa Pers., Samanea saman (Jacq.) Merr., Butea monosperma (Lam.) Taub., Mangifera india L., Syzygium cumini (Linn.) Skeels, Terminalia belerica Roxb., Amoora rohituka W. & A, Sterculia villosa Roxb etc. The ecological distributional survey of the ferns and fern allies in the Jalpaiguri district is of great significance due to its richness and conservation value. This has attracted numerous researchers in the past and present. Pteridophytes make up a significant portion of plant diversity and are renowned for having exquisite leaf fronds. The following are comprehensive descriptions of the pteridophytes discovered in the study area, arranged according to C. R. Fraser-Jenkins [76].
 | Plate 1: (A) Huperzia squarrosa (Froster) Trevisan; (B) Huperzia phlegmaria (L.) Rothm.; (C) Ophinoglossum reticulatum L.; (D) Helminthostachys zeylanica (L.) Hook.; (E) Equisetum ramosissimum Desf.; (F) Equisetum arvense L. subsp. Diffusum (D. Don) Fraser-Jenkins; (G) Lycopodium japonicum Thunberg.; (H) Dicranopteris linearis (Burm. f.) Underw.
[Click here to view] |
 | Plate 2: (A) Thelypteris triphylla (Sw.) Iwatsuki; (B) Thelypteris dentata (Forssk.) Brown. & Jermy, (C) Thelypteris nudata (Roxb.) Morton; (D) Thelypteris arida (Don) Morton; (E) Thelypteris procera (D. Don) Fraser-Jenk.; (F) Thelypteris torresiana (Gaudich) Alston; (G) Asplenium crinicaule Hance; (H) Asplenium finalysonianum Wall. ex Hook et Grev.
[Click here to view] |
 | Plate 3: (A) Nephrolepis cordifolia (L.) C. Presl.; (B) Nephrolepis radicans (Burm. f.) Kuhn.; (C) Vittaria elongata Swartz; (D) Drynaria quercifolia (L.) J. Sm.; (E) Antrophyum reticulatum (G. Forst.) Kaulf.; (F) Microsorum cuspidatum (D. Don) Tagawa; (G) Microsorum puncatum (L.) Copeland; (H) Leptochilus decurrens Blume ssp. hemionitideus Fraser-Jenk.
[Click here to view] |
 | Plate 4: (A) Salvinia natans (L.) All.; (B) Salvinia cucullata Bory.; (C) Salvinia molesta D. Mitch.; (D) Azolla pinnata R. Br.; (E) Adiantum philippense L.; (F) Adiantum incisum Forssk. subsp. incisum Fraser-Jenk.; (G) Adiantum caudatum Klotz.; (H) Adiantum capillus-veneris L.; (I) Ceratopteris thalictroides (L.) Brongn.
[Click here to view] |
 | Plate 5: (A) Pteris alata L.; (B) Pteris ensiformis Burm. f.; (C) Pteris scabririgens Fraser-Jenk. & S.C. Verma; (D) Coniogramme serrulata (Blume) Fee.; (E) Pteris vittata L. subsp. vittata; (F) Pteris cretica L. ssp. Cretica; (G) Pteris multifida Poir.; (H) Pteris biaurita L. subsp. Walkeriana Fraser-Jenk. & Dom. Rajkumar; (I) Pteris kathmanduensis Fraser-Jenk. & T.G.Walker.
[Click here to view] |
 | Plate 6: (A) Aleuritopteris bicolor (Roxb.) Fraser-Jenk.; (B) Pityrogramma calomelanos (L.) Link.; (C) Onychium siliculosum (Desv.) Christ.; (D) Odontosoria chinensis subsp. chinensiss (L.) Smith; (E) Microlepia rhomboidea (Wall. ex Kunz.) Prantl; (F) Davallia trichomanoides Blume; (G) Blechnum orientale L.; (H) Lygodiu flexuosum (L.) Sw.; (I) Lygodium microphyllum (Cav.) R. Br.
[Click here to view] |
 | Plate 7: (A) Pyrrosia costata (C. Presl ex Bedd.) Tagawa & K. Iwats; (B) Pyrrosia mannii (Giesenh) Ching.; (C) Pyrrosia stenophylla (Bedd.) Ching.; (D) Tectaria codnuta (J. Smith) C. Christensen.; (E) Tectaria polymorpha (Wall. ex Hook.) Copeland; (F) Dryopteris cochleata (D. Don) C. Chr.; (G) Polystichum lentum (D. Don) T. Moore; (H) Lindsaea ensifolia Sw.; (I) Marsilea minuta L.; (J) Diplazium esculentum (Retz.) Sw.; (K) Microlepia speluncae (Linn.) Moore; (L) Cyathea gigantea (Wal. ex. Hook.) Holttum.; (M) Selaginella repanda (Desv. ex Poir.) Spring.; (N) Selaginella chrysocaulos (Hooker & Greville) Spring.; (O) Lepisorus contortus (Christ.) Ching.
[Click here to view] |
 | Figure 3: Graphical representation of habitat distribution of pteridophytes of Jalpaiguri.
[Click here to view] |
5. CHECKLIST OF PTERIDOPHYTE (FERNS AND FERN-ALLIES) OF JALPAIGURI DISTRICT
FERN-ALLIES
1. LYCOPODIACEAE
1.1 Huperzia squarrosa (Froster) Trevisan: Epiphytic. Khumai, Chalsa (Matiali). Elevation: ca. 150-250 m.
Material: M Dey MD025/21, 28/07/2021 (ARUN!), M Dey H1104 (GMSMH).
1.2 Huperzia phlegmaria (L.) Rothm.: Epiphytic. Chalsa view point, Matiali bazar. Elevation: ca. 300-350 m.
Material: M Dey & A K Soni MD015/21, 28/07/2021 (ARUN!), M Dey H1101 (GMSMH).
1.3 Lycopodium japonicum Thunberg.: Terrestrial. Bagrakote GoodrickeTea garden (Mal), Jiti Tea Garden. Elevation: ca. 280-370 m.
Material: M Dey & A K Soni MD008/20, 23/01/2020 (ARUN!), M Dey E0144 (GMSMH).
1.4 Lycopodiella cernua (L.) Pich. Sermolli: Terrestrial, Epiphytic. Odlabari, Chamurchi, Belakoba, Jalpaiguri town. Elevation: ca. 100-200 m.
Material: M Dey MD144/20, 23/10/2020 (ARUN!), M Dey E2041 (GMSMH).
2. SELAGINELLACEAE
2.1 Selaginella monospora Spring.: Lithophytic, marshy habitat- alongside the tea garden canal. Raipur tea garden; Panikauri (Fatapukur), Nathua (Dhupguri). Elevation: ca. 50-100 m.
Material: M Dey & A K Soni MD057/20, 24/05/2020 (ARUN!), M Dey C4209 (GMSMH).
2.2 Selaginella repanda (Desv. ex Poir.) Spring.: Lithophytic, Terrestrial. Denguajhar tea garden, Raipur-Joypur tea grden; Borodighi tea garden, Bagrakote, Nagrakata. Elevation: ca. 50-100 m.
Material: M Dey & A K Soni MD019/19, 01/05/2019 (ARUN!), M Dey A0068 (GMSMH).
2.3 Selaginella bisulcata Spring.:Lithophytic. Matiali Tea garden, Matiali bazar.Elevation: ca. 350 m.
Material: M Dey MD031/20, 03/05/2020 (ARUN!), M Dey C2211 (GMSMH).
2.4 Selaginella chrysocaulos (Hooker & Greville) Spring.: Lithophytic. Dumdim (Mal), Samsing. Elevation: ca. 300 - 450 m.
Material: M Dey & A K Soni MD014/20, 23/01/2020 (ARUN!), M Dey B1210 (GMSMH).
2.5 Selaginella ciliaris (Retz.) Spring.: Lithophytic, marshy habitat- alongside the tea garden canal. Odlabari tea garden, Apalchad forest. Elevation: ca. 250 m.
Material: M Dey MD089/23, 20/02/2023 (ARUN!), M Dey C2320 (GMSMH).
2.6 Selaginella subdiaphana (Wallich ex Hooker & Greville) Spring.:Lithophytic. Khumai, Sevoke. Elevation: ca. 200-250 m.
Material: M Dey & A K SoniMD041/21, 15/08/2021 (ARUN!), M Dey H1714 (GMSMH).
3. EQUISETACEAE
3.1 Equisetum ramosissimum Desf.: Semi aquatic, Marshy habitat. Model school campus (Kranti), Sevoke. Elevation: ca. 150 m.
Material: M Dey & A K Soni MD015/20, 26/01/2020 (ARUN!), M Dey G2320 (GMSMH).
3.2 Equisetum arvense Linn. subsp. Diffusum (D. Don) Fraser-Jenkins: Semi aquatic. Sevoke. Elevation: ca. 250 m.
Material: M Dey MD042/22, 15/08/2022 (ARUN!), M Dey W1110 (GMSMH).
FERNS
4. OPHIOGLOSSACEAE
4.1 Helminthostachys zeylanica (L.) Hook.: Terrestrial, marshy habitat. Moraghat, Ramsai. Elevation: ca. 90 m.
Material: M Dey MD668/22, 10/07/2022 (ARUN!), M Dey V0615 (GMSMH).
4.2 Ophioglossum reticulatum Linn.: Terrestrial. Jalpaiguri Sonali Girls school campus; A.C. College playground. Elevation: ca. 80 m.
Material: M Dey & A K Soni MD010/19, 19/04/2019 (ARUN!), M Dey A0847 (GMSMH).
5. MARATTIACEAE
5.1 Angiopteris crassipes Wall. Ex C. Presl.: Terrestrial, shade loving habitat. Targhera forest, Apalchad forest. Elevation: ca. 140 m.
Material: M Dey & A K Sarkar MD049/24, 24/03/2024 (GMSMH).
6.1 Lygodiu flexuosum (L.) Sw.: Terrestrial. Lataguri forest, Murti beat, throughout the district. Elevation: ca. 80- 300 m.
Material: M Dey & A K Soni MD025/19, 29/05/2019 (ARUN!), M Dey A2568 (GMSMH).
6.2 Lygodium japonicum (Thunb. in Murray) Sw.: Terrestrial. Samsing. Elevation: ca. 350 m.
Material: M Dey MD109/19, 18/09/2019 (ARUN!), M Dey A3004 (GMSMH).
6.3 Lygodium microphyllum (Cav.) R. Br.: Terrestrial. Khumai. Elevation: ca. 300 m.
Material: M Dey & A K Soni MD095/19, 08/09/2019 (ARUN!), M Dey A2898 (GMSMH).
7. MARSILEACEAE
7.1 Marsilea minuta L.: Aquatic. Boulbari, Singimari, Paharpur more. Elevation: ca. 80 m.
Material: M Dey MD027/19, 29/05/2019 (ARUN!), M Dey A1844 (GMSMH & NBUH).
8. GLEICHENIACEAE
8.1 Dicranopteris linearis (Burm. f.) Underw.: Terrestrial. Denguajhar tea garden. Elevation: ca. 100 – 300 m.
Material: M Dey & A K Soni MD009/19, 30/03/2019 (ARUN!), M Dey A0241 (GMSMH).
9. POLYPODIACEAE
9.1 Microsorum cuspidatum (D. Don) Tagawa: Epiphytic. Meteli, Khumai, Samsing. Elevation: ca. 300-400 m.
Material: M Dey & A K Soni MD079/21, 26/09/2021 (ARUN!), M Dey R3305 (GMSMH).
9.2 Microsorum puncatum (L.) Copeland: Epiphytic, lithophytic. Lataguri forest road side area. Elevation: ca. 140 m.
Material: M Dey & A K Soni MD112/19, 08/09/2019 (ARUN!), M Dey D3118 (GMSMH).
9.3 Drynaria quercifolia (L.) J. Sm.: Epiphytic, lithophytic. Park more - Pandapara road (Jalpaiguri). Elevation: ca. 80 m.
Material: M Dey & A K Soni MD015/19, 26/04/2019 (ARUN!), M Dey A0072 (GMSMH & NBUH).
9.4 Drynaria propinqua (Wall. ex Mett.) J. Sm. ex Bedd.: Epiphytic. Chapramari reserve forest. Elevation: ca. 250 m.
Material: M Dey MD558/23, 14/02/2023 (ARUN!), M Dey Z6233 (GMSMH).
9.5 Pyrrosia costata (C.Presl ex Bedd.) Tagawa & K. Iwats: Epiphytic. Salbari more (Matiali), khunia more. Elevation: ca. 150-180 m.
Material: M Dey & A K Soni MD039/20, 03/05/2020 (ARUN!), M Dey B1093 (GMSMH & NBUH).
9.6 Pyrrosia mannii (Giesenh) Ching.: Epiphytic, lithophytic. BSNL office quarters boundary wall (Jalpaiguri). Elevation: ca. 80 m.
Material: M Dey & A K Soni MD044/19, 16/07/2019 (ARUN!), M Dey B1192 (GMSMH).
9.7 Pyrrosia lanceolata (L.) Farwell: Epiphytic - lithophytic. Gairkata Bus-stand (Dhupguri). Elevation: ca. 100 m.
Material: M Dey & A K Soni MD022/19, 07/05/2019 (ARUN!), M Dey A2898 (GMSMH & NBUH).
9.8 Pyrrosia stenophylla (Bedd.) Ching.: Epiphytic. Khumai, Sipchu SSB camp. Elevation: ca. 300 m.
Material: M Dey & A K Soni MD984/22, 03/12/2019 (ARUN!), M Dey Z8894 (GMSMH).
9.9 Lepisorus contortus (Christ.) Ching.: Epiphytic, lithophytic. Khunia more (Nagrakata). Elevation: ca. 200 m.
Material: M Dey & A K Soni MD116/21, 24/10/2021 (ARUN!), M Dey S5689 (GMSMH).
9.10 Leptochilus decurrens Blume ssp. hemionitideus Fraser-Jenk.: Lithophytic, terrestrial. Bagrakote (Mal). Elevation: ca. 300 m.
Material: M Dey & A K Soni MD085/21, 03/10/2021 (ARUN!), M Dey R4207 (GMSMH).
9.11 Loxogramme involuta (D.Don) C.Presl.: Epiphytic. Matiali, Sumsing. Elevation: ca. 300-350 m.
Material: M Dey & A K Soni MD081/21, 26/09/2021 (ARUN!), M Dey P8455 (GMSMH).
9.12 Loxogramme porcata Prince: Epiphytic. Chapramari reserve forest. Elevation: 400 m.
Material: M Dey & A K Soni MD202/22, 18/07/2022 (ARUN!), M Dey T7684 (GMSMH).
10. CYATHEACEAE
10.1 Cyathea gigantea (Wall. ex. Hook.) Holttum.: Lataguri forest, Jurabandha road side. Elevation: ca. 80-150 m.
Material: M Dey & A K Soni MD020/20, 26/01/2020 (ARUN!), M Dey D1453 (GMSMH).
11. DENNSTAEDTIACEAE
11.1 Hypolepis polypodioides (Blume) Hooker: Terrestrial. Panapara kalibari road side. Elevation: ca. 50 m.
Material: M Dey & A K Soni MD061/19, 11/08/2019 (ARUN!), M Dey A2100 (GMSMH).
11.2 Microlepia speluncae (Linn.) Moore: Terrestrial. Lataguri forest, Jalpaiguri town.Elevation: ca. 50-100 m.
Material: M Dey & A K Soni MD107/19, 08/09/2019 (ARUN!), M Dey A2135 (GMSMH & NBUH).
11.3 Microlepia rhomboidea (Wall. ex Kunz.) Prantl: Terrestrial. Khunia more, Samsing, Sipchu forest, khumai. Elevation: ca. 130-250 m.
Material: M Dey & A K Soni MD055/21, 15/08/2021 (ARUN!), M Dey K6245 (GMSMH).
12. LINDSAEACEAE
12.1 Lindsaea ensifolia Sw.: Terrestrial. Sipchu SSB camp, Khumai. Elevation: ca. 200-300 m.
Material: M Dey & A K Soni MD003/19, 28/03/2019 (ARUN!), M Dey D0062, 09/08/2021 (GMSMH).
12.2 Odontosoria chinensis subsp. chinensis (L.) Smith: Terrestrial. Denguajhar tea garden. Elevation: ca. 80 m.
Material: M Dey & A K Soni MD057/19, 04/08/2019 (ARUN!), M Dey A2898 (GMSMH & NBUH).
13. PTERIDACEAE
13.1 Adiantum philippense L.: Lithophytic. On the wall of Ashram para more (Jalpaiguri). Elevation: ca. 80 m.
Material: M Dey & A K Soni MD077/20, 02/08/2020 (ARUN!), M Dey E6911 (GMSMH & NBUH).
13.2 Adiantum capillus-veneris L.: Lithophytic. On the wall of Ashram para more (Jalpaiguri). Elevation: ca. 80 m.
Material: M Dey & A K Soni MD058/19, 11/08/2019 (ARUN!), M Dey C0909 (GMSMH).
13.3 Adiantum caudatum Klotz.: Lithophytic. Municipality Health centre, Congress para (Jalpaiguri). Elevation: ca. 80 m.
Material: M Dey & A K Soni MD046/19, 16/07/2019 (ARUN!), M Dey C3364 (GMSMH).
13.4 Adiantum incisum Forssk. subsp. incisum Fraser-Jenk.: Lithophytic, epiphytic. Wall of BSNL housing (Jalpaiguri), Chalsa. Elevation: ca. 80-300 m.
Material: M Dey & A K Soni MD104/21, 17/10/2021 (ARUN!), M Dey T2450 (GMSMH).
13.5 Aleuritopteris bicolor (Roxb.) Fraser-Jenk.: Lithophytic, Terrestrial. Diana forest, Sevoke. Elevation: ca. 150-250 m.
Material: M Dey & A K Soni MD127/20, 27/09/2020 (ARUN!), M Dey E1235 (GMSMH).
13.6 Ceratopteris thalictroides (L.) Brongn.: Aquatic. Rajbari pond, road side ditch at Paharpur, Jalpaiguri. Elevation: ca. 70-100 m.
Material: M Dey & A K Soni MD069/20, 02/08/2020 (ARUN!), M Dey E1130 (GMSMH & NBUH).
13.7 Coniogramme serrulata (Blume) Fee.: Lithophytic, Terrestrial. Aibheel tea garden. Elevation: ca. 300 m.
Material: M Dey & A K Soni MD177/22, 13/11/2022 (ARUN!), M Dey X3411 (GMSMH).
13.8 Onychium siliculosum (Desv.) Christ.: Terrestrial. Chapadanga (near 70 more). Elevation: ca. 100 m.
Material: M Dey & A K Soni MD059/21, 15/08/2021 (ARUN!), M Dey M5541 (GMSMH).
13.9 Pityrogramma calomelanos (L.) Link.: Terrestrial, Lithophytic. Koranipara (Jalpaiguri). Elevation: ca. 80 m.
Material: M Dey & A K Soni MD079/20, 02/08/2020 (ARUN!), M Dey F3524 (GMSMH & NBUH).
13.10 Pteris vittata L. subsp. vittata: Lithophytic. Gairkata Bus stand, Salbari (Dhupguri). Elevation: ca. 50-200 m.
Material: M Dey & A K Soni MD023/19, 07/05/2019 (ARUN!), M Dey B0902 (GMSMH & NBUH).
13.11 Pteris alata L.: Terrestrial. Gairkata, Banarhat (Dhupguri). Elevation: ca. 80-300 m.
Material: M Dey & A K Soni MD091/19, 01/09/2019 (ARUN!), M Dey B1365 (GMSMH).
13.12 Pteris biaurita L. subsp. fornicata Fraser-Jenk.: Terrestrial. Sipchu SSB camp. Elevation: ca. 200-300 m.
Material: M Dey & A K Soni MD115/19, 08/09/2019 (ARUN!), M Dey B1426 (GMSMH).
13.13 Pteris biaurita L. subsp. Walkeriana Fraser-Jenk. & Dom. Rajkumar: Terrestrial. Lataguri forest, Diana forest. Elevation: ca. 100-300 m.
Material: M Dey & A K Soni MD117/19, 08/09/2019 (ARUN!), M Dey B1459 (GMSMH).
13.14 Pteris cretica L. ssp. Cretica: Terrestrial, Lithophytic. Dumdim Tea garden, Sevoke. Elevation: ca. 350 m.
Material: M Dey & A K Soni MD071/21, 12/09/2021 (ARUN!), M Dey J6044 (GMSMH).
13.15 Pteris aspericaulis Wall. ex J. Agardh.: Terrestrial. RPF training centre (Domohoni). Elevation: ca. 100 m.
Material: M Dey MD233/22, 20/10/2022 (ARUN!), M Dey P0161 (GMSMH).
13.16 Pteris ensiformis Burm. f.: Terrestrial. Teesta udyan park, Jalpaiguri Holy Child school campus. Elevation: ca. 80-100 m.
Material: M Dey & A K Soni MD198/22, 16/09/2022 (ARUN!), M Dey P0085 (GMSMH).
13.17 Pteris kathmanduensis Fraser-Jenk. & T.G.Walker: Lithophytic. Domohoni-Basusuba road side. Elevation: ca. 90 m.
Material: M Dey & A K Soni MD335/22, 02/11/2022 (ARUN!), M Dey V5514 (GMSMH).
13.18 Pteris multifida Poir.: Lithophytic. DWO office wall (near PWD more), Jalpaiguri. Elevation: ca. 90 m.
Material: M Dey & A K Soni MD239/22, 11/07/2022 (ARUN!), M Dey T4612 (GMSMH).
13.19 Pteris scabririgens Fraser-Jenk. & S.C. Verma: Terrestrial. Sipchu – Khumai road side. Elevation: ca. 250 m.
Material: M Dey & A K Soni MD377/22, 02/12/2022 (ARUN!), M Dey Z0873 (GMSMH).
14. VITTARIACEAE
14.1 Antrophyum reticulatum (G. Forst.) Kaulf.: Epiphytic. Lataguri road side, Khumai. Elevation: ca. 150-350 m.
Material: M Dey & A K Soni MD082/21, 26/09/2021 (ARUN!), M Dey J2291 (GMSMH).
14.2 Vittaria elongata Swartz: Epiphytic. Road side area of Pandapara (Jalpaiguri), Ramsai forest. Elevation: ca. 80-300 m.
Material: M Dey & A K Soni MD083/20, 02/08/2020 (ARUN!), M Dey E7014 (GMSMH).
15. ASPLENIACEAE
15.1 Asplenium crinicaule Hance: Epiphytic. Matiali High school more. Elevation: ca. 250 m.
Material: M Dey & A K Soni MD034/20, 03/05/2020 (ARUN!), M Dey D4406 (GMSMH).
15.2 Asplenium nidus L.: Epiphytic. Salbari more (near Chalsa). Elevation: ca. 200 m.
Material: M Dey & A K Soni MD075/19, 15/08/2019 (ARUN!), M Dey B4004 (GMSMH).
15.3 Asplenium finlaysonianum Wall. ex Hook et Grev.: Epiphytic. Near Bagrakote Army camp, Sevoke. Elevation: ca. 300 m.
Material: M Dey & A K Soni MD039/19, 14/07/2019 (ARUN!), M Dey A6231 (GMSMH).
16. THELYPTERIDACEAE
16.1 Thelypteris nudata (Roxb.) Morton: Terrestrial. Road side area of Lataguri forest, Adabari (Moulani). Elevation: ca. 130 m.
Material: M Dey & A K Soni MD029/20, 03/05/2020 (ARUN!), M Dey C2454 (GMSMH & NBUH).
16.2 Thelypteris triphylla (Sw.) Iwatsuki: Terrestrial. Sipchu SSB camp, Khumai, Nagrakata. Elevation: ca. 200-300 m.
Material: M Dey & A K Soni MD040/19, 14/07/2019 (ARUN!), M Dey B3332 (GMSMH & NBUH).
16.3 Thelypteris dentata (Forssk.) Brown. & Jermy: Terrestrial. Duck bunglow para, Dhupguri. Elevation: ca. 100 m.
Material: M Dey & A K Soni MD092/19, 01/09/2019 (ARUN!), M Dey A2990 (GMSMH).
16.4 Thelypteris arida (Don) Morton: Terrestrial. Belakoba, Sulkapara. Elevation: ca. 80-150 m.
Material: M Dey & A K Soni MD066/21, 30/08/2021 (ARUN!), M Dey E4457 (GMSMH).
16.5 Thelypteris torresiana (Gaudich) Alston: Terrestrial. Pandapara Park more. Elevation: ca. 80 m.
Material: M Dey & A K Soni MD073/21, 15/09/2021 (ARUN!), M Dey E5628 (GMSMH).
16.6 Thelypteris procera (D. Don) Fraser-Jenk.: Terrestrial. Lataguri forest near Mahakal mandir. Elevation: ca. 120 m.
Material: M Dey & A K Soni MD123/21, 24/10/2021 (ARUN!), M Dey S1728 (GMSMH).
16.7 Thelypteris interrupta (Wild.) K. Iwats.: Terrestrial. Nathua forest. Elevation: ca. 100 m.
Material: M Dey MD989/22, 24/09/2022 (ARUN!), M Dey V70284 (GMSMH).
17. WOODSIACEAE
17.1 Diplazium esculentum (Retz.) Sw.: Terrestrial. Pandapara roadside (Jalpaiguri). Elevation: ca. 80 m.
Material: M Dey & A K Soni MD007/19, 28/03/2019 (ARUN!), M Dey A0012 (GMSMH & NBUH).
18. DRYOPTERIDACEAE
18.1 Dryopteris cochleata (D. Don) C. Chr.: Marshy habitat. Sipchu forest beat. Elevation: ca. 310 m.
Material: M Dey & A K Soni MD109/21, 24/10/2021 (ARUN!), M Dey K3245 (GMSMH).
18.2 Polystichum lentum (D. Don) T. Moore: Terrestrial. Khumai, Khunia more. Elevation: ca. 200-3000 m.
Material: M Dey & A K Soni MD121/20, 27/09/2020 (ARUN!), M Dey H6312 (GMSMH).
18.3 Polystichum pseudotsus-simense Ching: Terrestrial, marshy habitat. Khumai more. Elevation: ca. 340 m.
Material: M Dey & A K Soni MD123/20, 27/09/2020 (ARUN!), M Dey H6320 (GMSMH).
18.4 Polystichum manmeiense (Christ) Nakaike: Terrestrial. Jhalong road side, Khunia more. Elevation: ca. 400 m.
Material: M Dey & A K Soni MD195/22, 18/07/2022 (ARUN!), M Dey W3210 (GMSMH).
18.5 Polystichum nepalense (Spreng.): Lithophytic. Meenglas tea garden (Matiali). Elevation: ca. 280 m.
Material: M Dey & A K Soni MD200/22, 18/07/2022 (ARUN!), M Dey W3222 (GMSMH).
18.6 Tectaria codnuta (J. Smith) C. Christensen: Terrestrial. Meenglas tea garden, Khumai more. Elevation: ca. 250-340 m.
Material: M Dey & A K Soni MD133/20, 27/09/2020 (ARUN!), M Dey H6374 (GMSMH & NBUH).
18.7 Tectaria polymorpha (Wall. ex Hook.) Copeland: Terrestrial. Khunia more (Nagrakata). Elevation: ca. 180 m.
Material: M Dey & A K Soni MD125/21, 24/10/2021 (ARUN!), M Dey Q1516 (GMSMH).
19. OLEANDRACEAE
19.1 Nephrolepis cordifolia (L.) C. Presl.: Terrestrial. Khunia more. Elevation: ca. 180 m.
Material: M Dey & A K Soni MD051/21, 15/08/2021 (ARUN!), M Dey P4285 (GMSMH & NBUH).
19.2 Nephrolepis radicans (Burm. f.) Kuhn.: Epiphytic. Khumai, Khunia more. Elevation: ca. 180-300 m.
Material: M Dey & A K Soni MD049/21, 15/08/2021 (ARUN!), M Dey P4210 (GMSMH).
20. DAVALLIACEAE
20.1 Davallia trichomanoides Blume: Epiphytic, climber. Khumai more. Elevation: ca. 280 m.
Material: M Dey & A K Soni MD145/20, 24/10/2020 (ARUN!), M Dey F2231 (GMSMH).
21. BLECHNACEAE
21.1 Blechnum orientale L.: Terrestrial. Koranipara canal (Jalpaiguri). Elevation: ca. 80 m.
Material: M Dey & A K Soni MD087/20, 02/08/2020 (ARUN!), M Dey G2231 (GMSMH & NBUH).
21.2 Stenochlaena palustris (Burm.) Bedd.: Climbing / creeping, Terrestrial. Meenglas tea garden (Matiali). Elevation: ca. 280 m.
Material: M Dey MD660/22, 28/06/2022 (ARUN!), M DeyP4740 (GMSMH).
22. AZOLLACEAE
22.1 Azolla pinnata R.Br.: Aquatic. Road side ditch at Maynaguri Road, Paharpur more. Elevation: 80-150 m.
Material: M Dey & A K Soni MD019/20, 26/01/2020 (ARUN!), M Dey C3256 (GMSMH).
23. SALVINIACEAE
23.1 Salvinia cucullata Bory: Aquatic. Chapadanga - 70 more (Kranti), Paharpur more. Elevation: 80-120 m.
Material: M Dey & A K Soni MD076/21, 18/09/2021 (ARUN!), M Dey T8694 (GMSMH).
23.2 Salvinia natans (L.) All.: Aquatic. Chapadanga - 70 more (Kranti), Barnish, Domohoni (Maynaguri). Elevation: 80-150 m.
Material: M Dey & A K Soni MD074/21, 18/09/2021 (ARUN!), M Dey T8617 (GMSMH).
23.3 Salvinia molesta D.Mitch.: Aquatic. Gajoldoba (Rajganj). Elevation: 140 m.
Material: M Dey MD799/22, 06/10/2022 (ARUN!), M Dey Z7822 (GMSMH).
Among the listed plants some are very common, where as some are less frequent. Unlike the rare species, certain ferns exhibit a high degree of local abundance, making them a distinctive attribute of their specific geographic locations. The presence of a wide range of species in the district, combined with the delicate ecological balance caused by human-induced stress, requires the implementation of suitable conservation strategies to safeguard pteridophyte community. Preparation of Checklist of pteridophytes after a time interval is very important task for researchers as this plant group can be influenced by environmental phenomena such as earthquakes, floods, and the biological characteristics of the species, including the separation of male and female plants. The combination of human disturbance and global climate change poses a significant threat to plant diversity on a global scale, leading to habitat loss and fragmentation. Certain species of ferns require specific conservation efforts due to their increasing scarcity in the natural environment. One potential approach to preserving pteridophytes in the study area is the establishment of protected area specifically designated for this purpose. The majority of research on pteridophytes has focused on their ecological structure, with limited attention given to the variation in diversity that occurs along gradients of elevation.
6. CONCLUSION
The study revealed the presence of various fern species as well as allied species, inside the territory of the district Jalpaiguri which holds significant importance in the context of plant biodiversity. Our findings state that diversity of pteridophytes is remarkable and the distribution of the species changes according to the habitats, sediment properties, orientation and coexistence of other plants within the same niche. Within this region pteridophytes are able to survive in a wide range of habitats where most flowering plants would perish, including cracks in rocks and branches. Currently, numerous ecological niches face significant threats as a result of diverse anthropogenic activities, posing a substantial challenge to the survival of peridophytes in the region. The outcomes of the study would ultimately establish a foundational investigation into the variety of Pteridophytes in Jalpaiguri, encompassing their habitats and conservation status. Additionally, it would serve as a main data resource for subsequent research conducted by the scientific community.
7. ACKNOWLEDGMENTS
We convey our gratitude to Dr. Vineet K. Rawat, Scientist- E, Botanical Survey of India, Arunachal Pradesh Regional Centre for his kind cooperation during identification.
8. FINANCIAL SUPPORT AND SPONSORSHIP
We have not received any grant from anywhere.
9. AUTHOR CONTRIBUTIONS
All the authors listed have made a substantial, direct and intellectual contribution to the work, and approved it for publication. All the authors had the idea for the article; MD, AKSo and AKSa performed the research work and data analysis; MD, SSA and AKSa drafted; figures were prepared by MD and AKSa; SSA and AKSa critically revised the work.
10. CONFLICTS OF INTEREST
The authors report no financial or other conflicts of interest in this work.
11. DATA AVAILABILITY
Data supporting this study are included within the article.
12. ETHICAL APPROVALS
This study does not involve experiments on animals or human subjects.
13. PUBLISHER’S NOTE
All claims expressed in this article are solely those of the authors and do not necessarily represent those of the publisher, the editors and the reviewers. This journal remains neutral with regard to jurisdictional claims in published institutional affiliation.
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