FRLHT Indian Medicinal Plants Nomenclature Database with images/ herbarium, distribution, local names etc. : 

Species with description & pictures in Flowers of India as on 27.4.14: 

1. Inflorescence a head on raised stalk

     2. Plants with thick reddish leaves, atleast ¾ as broad as long; cultivated as hedge/border plant ...........................1. A. brasileana (incl. A. dentata)

     2. Leaves not reddish, less than ½ as broad as long; wild plant of moist or aquatic habitats. ..................................2. A.philoxeroides.

1. Inflorescence a sessile head in leaf axils

         3. Plants prostrate, mat-forming

4. Leaves atleast ¾ as broad as long, stems and leaves rigid; flowers (tepals) spine-tipped …...................3. A. pungens

4. Leaves usually less than ½ as broad as long, stems and leaves soft; flowers (tepals) not spin-tipped …4. A. paronychoides

3. Plants erect or spreading not mat-forming

    5. Leaves sessile, linear or narrowly oblanceolate; plant of moist or wet situations ………...................… 5. A. sessilis

    5. Leaves with distinct petiole; mostly cultivated

        6. Leaves green or tinged with purple; mostly oblanceolate, gradually narrowed into petiole, less than ½ as broad as long ………………………............................................................................................................….6. A. bettzickiana (incl. A. amoena and A. versicolor)

        6. Leaves green, not tinged with purple; mostly elliptic-ovate, more than ½ as broad as long, more sharply narrowed into short petiole…………………..……………..................................................................................................................7. A. ficoidea