The taxonomists still rely to a great extent on the morphological characteristics, because they are easily visible and can conventionally use in the classification of plants.

In addition to the con­ventional morphological characteristics that are now popular to the students, other characteristics like habit, underground organs, leaves, seedling morphology, stipules, non-conventional charac­teristics of floral parts, seeds etc. are used in the identification of various groups of plants.

Size, branching pattern, spread, density etc. of a plant are treated com­monly in taxonomic description. The shape of a tree i.e., bushy, umbrella- shaped, flat topped, cylindric, oblong etc. are used for the recognition of a tree. It is Excurrent in Polyalthea longifolia, Caudex in Cocos nucifera, Deliquescent in Mangifera indica, Culm in Bambusa tulda, etc. The characteris­tics of bark (colour, thickness, fissuring, texture etc.) are used to distinguish different species of Betula and Pinus.

Generally the underground parts are not collected during the preparation of a Herbarium. In some cases, they have been shown to be very useful in the identification of different taxa. Chouard (1936) have used the characteristics of bulbs and underground parts in the classification of Scilleae of Liliaceae. In Liliaceae two species of Chlorophytum viz. C. glaucoides Blatt. and C. glaucum Dalz. are morphologically alike except the cha­racteristics of underground parts.

In C. glaucoides the root-fibres are slender and end in ellipsoid tubers, while in C. glaucum the root fibres are thick and without terminal tubers. The structure and morphology of root-tubers are used in the differentiation of large number of species in Dioscorea .

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