Rawat, D.S.Tamta, Ritika2019-01-222019-01-222018-07http://krishikosh.egranth.ac.in/handle/1/5810091984Fabaceae, also called Leguminosae or pea family, is the third largest family among the angiosperms with 741 genera and 20200 species on Earth. Contemporary scientific literature accept three subfamilies and 36 tribes in the family though recent classification by Legume Phylogeny Working Group has proposed six subfamilies in Fabaceae and placed earlier subfamily Mimosoideae embedded in Caesalpinioideae. Trichomes are invariably present on the legume species. Large number of Fabaceae members exists in Pantnagar area and a study of trichomes of 53 species and one subspecies belonging to 39 genera, 18 tribes and 3 subfamilies was conducted during 2017-18. Thirteen different surfaces of plant parts- stem, petiole, petiolule, both surfaces of leaf or leaflet blade and its margin, stipule, rachis, sepal, petal, gynoecium, androecium, pod, were examined for presence and types of trichomes. One species Caesalpinia pulcherrima was found completely glabrous while 31 types of trichomes were recorded in 53 examined taxa. Trichomes were recorded on leaf or leaflet blade in 48 taxa, on stem in 45 taxa, on petiole in 44 taxa, on gynoecium in 41 taxa, on sepals in 39 taxa, on rachis in 37 taxa, on stipule in 35 taxa, on petiolule in 27 and on petals on 15 taxa. Only non-glandular trichomes were recorded in 22 species while rest 32 taxa bear both, non-glandular and glandular trichomes. Non-glandular unicellular subulate trichomes are widespread in Fabaceae and recorded in 29 taxa while glandular multicellular clavate trichomes are most common secretary trichomes recorded in 16 taxa. Maximum five types of trichomes were recorded on Phaseolus vulgaris and Desmodium gangeticum. In family Fabaceae trichome structure and distribution were found useful for differentiating subfamilies, tribes, genera and species of studied taxa thus proves their systematic utility.ennullThesis