In the description of Angiosperms, family is the most useful taxonomic unit. Ranks higher than family are not of much practical significance and are used mostly in classification systems and academic discussions. The taxonomic category genus also does not get much importance as plants are scientifically described in binomial nomenclature. Use of only the generic name isolated from the specific name may lead to confusion. The genus Solanum includes several species of which Solanum tuberosum alone represents the potato plant.
Family Poaceae (Graminae)

It is one of the largest families in monocots consisting of 620 genera and about 6000 species. Members are cosmopolitan in distribution. Around 900 species are present in India.
Family Liliaceae

It is commonly called Lily family. It includes about 250 genera and 3700 species that have a cosmopolitan distribution. Around 200 species are available in India.
Family Fabaceae

Leguminosae is one of the largest families in dicots, including about 690 genera and nearly 18,000 species. In all the major systems of classification, the family Leguminosae has been traditionally considered to include three sub families Papillionaceae, Caesalpinae and Mimosae. On the basis of vegetative characters, it is very difficult to characterise the sub families. However, the following features, with some exception, can be considered as common to all the three subfamilies of Leguminosae.
Sub Family Papillionatae (= Faboideae)

Habit: Mostly perennial herbs and shrubs, trees are also common. Some are climbers (Pisum, Lathyrus).
Sub Family: Caesalpiniodeae (Caesalpinae)

Habit: Mostly trees and shrubs, rarely herbs, some are climbers (Bauhinia).
Sub Family: Mimosae (Mimosoidae)

Habit: Herbs (Mimosa), shrubs and trees (Acacia).
Family Brassicaceae (= Cruciferae)

This family is commonly called as 'mustard family'. It includes about 300 genus and about 3700 species. The members have a cosmopolitan distribution. There are around 150 species in India.
Family Solanaceae

Solanaceae is commonly called as 'Brinjal family'. It includes about 90 genera and 2000 species. Members have a cosmopolitan distribution. There are around 60 species found in India.
Family Asteraceae

Commonly known as sunflower family. It is the largest family in dicots. It includes about 900 genera and 13,000 species. It has a cosmopolitan distribution. There are around 100 species in India.