Nelumbo - The Bulletin of the Botanical Survey of India

N. Ramayya ¹

Affiliations
1 Department of Botany, Osmania University, Hyderabad-A. P., IN

Abstract

Seventy two Compositae belonging to 56 genera representing the thirteen tribes of the family have been investigated in this study, Trichomes are recognised broadly into two categories namely the 'vegetative' and the 'floral' ones. It is the former that have been presently taken up for detailed investigations. In all 35 trichome types are found so far in the family. Of these, 15 have been described by previous workers which the present author has also observed in the species under investigation. Another 13 are the newly established types by the author. The remaining 7 represent types which the author has not come across during the present investigations but are described in the literature.

The general features of the trichomes in the family are discussed in the light of the present study. The trichomes are shown to exhibit in all four patterns in their structure which provide important evidence in the phylogeny of the trichomes.

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N. Ramayya ¹

Affiliations
1 Department of Botany, College of Science, Osmania University, Hyderabad-7 (A.P.), IN

Abstract

On the basis of the evidences from structural patterns, modes of development and metamorphic variations, the vegetative trichomes of the Compositae are shown to consist of four systems viz., I. Filiform System II. Macroform System III. M-Multiseriate System and P-Multiseriate System.

As Trichomes comprise more than one system, their phylogeny and classification needs to be studied separately within each system.

Evidences from the metamorphic variations and from the trichomes of the hybrids are shown to be of value in tracing the relationships. Netolitzky's (1932) phyletic dicta-which in general conform to the evolutionary principle 'simple to complex'-are considered to be useful in recognising the general primitive or advanced condition of a trichome within its system.

Within the systems, trichomes are shown, to be classifiable into the three morphological groups 'Papillae', 'Scales' and 'Hairs' adopted by Cowan (1950) for the trichomes in Rhododendron.

Studies on the trichomes of vascular plants in general are emphasized so that information could be available on the total number of their systems and distribution which will not only be of morphological value but also bf taxonomic significance.

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N. Ramayya ¹, T. Rajagopal ¹

Affiliations
1 Osmania University, Hyderabad, IN

Abstract

The paper presents an illustrated description of Elatine ambigua Wight and E. triandra Schkuhr (E. americana Arn.) of the family Elatinaceae with data on their distribution, pollen and general anatomy. The present collection of the two species from Ramappa and Pakhal, Andhra Pradesh, represents a second area of their distribution apart from Madras State. Additional features on their anatomy have been recorded. On the basis of field observations and anatomical features the species are grouped under floating-leaved anchored hydrophytes. The achlorophyllous epidermis and ledged guard cells, which are not in tune with typical characters of hydrophytes are regarded as of vestigial nature. E. ambigua is represented by two forms, one mesic and the other aquatic, which are considered to be ecoadaptive forms or ecads rather than two different genetic races. The anatomical characters are found to be too simplified to help in establishing the taxonomic position of the family.

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