Palynological studies in some species of Lamiaceae in Karnataka

Introduction:

            The Lamiaceae is a worldwide family with c. 236 genera and c. 7000 species. In New Guinea, it is represented by about 24 genera, including c. 75 species, of which nine genera and approximately half the species are arborescent; the others are herbs and often non-native (5). The members of this family are found to inhabit nearly all climatic conditions. Biochemically, they are characterized by the presence of essential oils, which makes many members of this family as wealth of species with medicinal properties and have great application in the pharmaceutical, cosmetic and perfume industry (8).  

            Pollen morphology of certain species of the family Lamicaeae in Saudi Arabia (4) reported 20 species in which 16 genera are covered with the pollen parameters like length, breadth, shape, surface, with colpi length and made them into groups and subgroups. Note on taxonomic implication of pollen morphology in Lamiaceae from Eastern Himalaya reported 14 species out of 12 genera from Eastern Himalaya with parameters like length, breadth of pollen, colpi number, size of colpi, with exine ornamentation (10).  A taxonomic revision of Anisomeles R.Br. (Lamiaceae), A.R. Bean reported 26 species are recognized and 18 species newly described (A. antrorsa A.R.Bean, A. brevipilosa A.R.Bean, A. bundeyensis A.R.Bean, A. carpentarica A.R.Bean, A. dallachyi A.R.Bean, A. eriodes A.R.Bean, A. farinacea A.R.Bean, A. grandibractea A.R.Bean, A. languida A.R.Bean, A. lappa A.R.Bean, A. leucotricha A.R.Bean, A. macdonaldii A.R.Bean, A. ornans A.R.Bean, A. papuana A.R.Bean, A. principis A.R.Bean, A. viscidula A.R.Bean, A. vulpina A.R.Bean, A. xerophila A.R.Bean), and one, A. ajugacea (F.M.Bailey & F.Muell). With its trichomes, cauline structure of leaf, and inner surface of calyx with key for identification (1). Pollen characterization and medicinal importance of Ocimum species of Lamiaceae from Telangana region of South India reported three species of Ocimum viz., Ocimum tenuiflorum, Ocimum gratissimum, and Ocimum basilicum, collected from theTelangana region of South India during 2022 was carried out by using Light Microscope (LM). The pollen grains showed variations in size, shape, with spheroidal to ellipsoidal shape. All the species had hexacolpate pollen grains. The exine is subtectate and sporoderm ornamentation is reticulate with variations in heterobrochate conditions with medicinal value (Antibacterial & Antiviral) (2).  Pollen Morphology of Teucrium L. (Lamiaceae, Ajugoideae) in Libya in their work reported Pollen Morphology of Teucrium L. (Lamiaceae, Ajugoideae) in Libya, reported palynological attributes for species characterization of Teucrium with special emphasis on the five Libyan endemics. Two main pollen shapes were documented, subprolate and prolate or perprolate in T. fruticans. The exine sculpture inspected at surface, operculum and pole were mostly verrucate, perforate or scabrate. Teucrium fruticans attained the phenomenon of pollen dimorphism with two distinct shapes and specifics sculpture for each form (7).

            Recently in Karnataka, Palynology has not been carried out, but nutlet morphology of 10 species of some Lamiaceae species has been carried out using a scanning electron microscope (11) and Achene morphology of some genera of Cyperaceae has been conducted using a Scanning electron microscope, ornamentation of the achene surface. Surface shows smooth, verrecose, trabeculate, punticulate. 12 species and six genera are given easy key up to genera based on seed shape and ornamentation (3).

Materials and methods:

            Collection of the specimens and identifying using different regional, district floras up to species level. Than dissected the flowers in a Magnus stero-microscope (1-4x), separated the anthers, stored in 70% alcohol. Than the anthers were dried then subjected to SEM analysis (9) and they were recorded based on Palynology glossary (6).   

Result & discussion:

            During a survey in Karnataka (Belgaum, Gadag, Dharwad, Uttara kannada district, Kodagu) collected 12 species belonging to8 genera (Anisomeles, Coleus, Isodon, Leucas, Ocimum, Plectranthus, Pogostemon, Teucrium) and palynological studies were conducted to study their variations and recorded the parameters of pollens (length and breadth ), length and breadth  of testa cells with various ornamentation on pollens. Parallel key up to species identification using palynology is given in this work.

US.-Undershrub; RS. Roadside; H. Herbs; E. Evergreen; SE. Semi evergreen; MD- Moist deciduous; Lateritic plateau; SG- Shola grassland.

            The study shows that these pollen can be broadly divided in several groups based on size, shape and surface structure. In the observed pollens has a range of ovoid to rhombus with minor variations. Shapes of testa cells were trigonal, tetragonal, pentagonal, hexagonal, spherical, and oval in different species. The majority of the shape of pollen and testa cells were similar. Pollen grains shows variation size among species with the measurement of length and breadth. S.E. values vary from species to species. Anisomeles indica (L.) Kuntze. Pollen was colpate, equatorial shapes oblate-spherical, pollen surface sculpturing-reticulate. Ocimum gratissimum L. has colpate, equatorial shape, oblate, pollen surface sculpturing finely lophoreticulate.  Leucas biflora (Vahl) Sm. has small testa cell arrangements with thick wall so we couldn’t get the measurements.

References:

1. Bear, A. R. (2015). A taxonomic revision of Anisomeles R.Br. (Lamiaceae). Austrobaileya  9(3): 321–381. 10.5962/p.299864
2. Chirranjeevi, M. and Chaya, P. (2023). Pollen characterization and medicinal importance of Ocimum species of Lamiaceae from Telangana region of South India. International Journal of Science and Research Archive. 08 (01), 960–964.  10.30574/ijsra.2023.8.1.0186
3. Deshi, S., Betageri, S., Patgar, V.G., and Kotresha, K. (2025). Achene morphology of some genera of Cyperaceae Juss. in Karnataka. Species. 26 (78): e41s3181
4. Doaigey, A. R. Mohamed Z., Ahmad A., Abd E. M. and T. Jacob (2018). Pollen morphology of certain species of the family Lamicaeae in Saudi Arabia. Saudi Journal of Biological Sciences. 25: 354-360. https://doi.org/10.1016/j.sjbs.2017.03.001
5. POWO “Plants of the World Online”, (2024) Facilitated by the Royal Botanic Gardens, Kew. Published on the internet: https://powo.science.kew.org//. Retrieved 08 October 2025.
6. Punt, W., Hoen, P. P., Blackmore, S., Nilsson, S. and Thomas A. L. (2006). Glossary of pollen and spore terminology. Review of Paleobotany & Palynology. 143: 1-81.
7. Ream, I. M., Salama, M. El.-D. and Askar, A. B. M. (2017). Pollen Morphology of Teucrium L. (Lamiaceae, Ajugoideae) in Libya. Bangladesh Journal Plant Taxonomists 24(2): 219–226. https://doi.org/10.3329/bjpt.v24i2.35118
8. Sharma, S. M. and Bhadange, D. G. (2013). Antimicrobial potential of Lamiaceae members. International Journal of Pharma. Sciences, 2013; 3(5):324-327.
9. Shreyas, B., and Kotresha, K. (2024). Seed morphometric with embryo diversity of wild orchids in North Karnataka. Journal of diversity studies, 3(2): 39-50. https://doi.org/10.51470/JOD.2024.03.02.39
10. Subira, B., Shreyasi, B., Baishakhi, S., Dulal, C. P., Maity, D., Das, A. P., and Sudhansu, S. D. (2022). Note on taxonomic implication of pollen morphology in Lamiaceae from Eastern Himalaya.  Journal Botany Society Bengal 76(1): 82-87. 
11. Yukti, K., Betageri, S., Patgar V. G. and K. Kotresha (2025). Nutlets morphology of some Lamiaceae in Karnataka. International Journal of Botany Studies. 10 (8): 39-43.