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BOTANY Higher Secondary Second Year - Textbooks Online

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1.3.5. SOLANACEAE – the potato family<br />

Systematic position<br />

Class: Dicotyledonae<br />

Sub-class: Gamopetalae<br />

Series: Bicarpellatae<br />

Order: Polemoniales<br />

Family: Solanaceae<br />

General characters<br />

Distribution<br />

Solanaceae includes about 90 genera and more than 2,800 species.<br />

The plants are widely distributed in tropical and subtropical regions. In<br />

India, this family is represented by 21 genera and 70 species.<br />

Habit<br />

Mostly annual herbs (eg. Solanum melongena), a few shrubs<br />

eg. Solanum torvum (Sundaikaai) and rarely trees (S. giganteum).<br />

Root<br />

A branched tap root system.<br />

Stem<br />

Aerial, erect, spinous eg. Solanum xanthocarpum (Kandangkathiri),<br />

herbaceous, woody, cylindrical, branched, hairy (eg. Petunia hybrida<br />

and Nicotiana alata). In S. tuberosum, the stem is modified into tuber.<br />

Leaf<br />

Petiolate, usually alternate, sometimes opposite, simple, entire (eg.<br />

Petunia hybrida), exstipulate and showing unicostate reticulate venation.<br />

In S. xanthocarpum, the midrib and veins are found with yellowish spines.<br />

Inflorescence<br />

Solitary, axillary cyme (eg. Datura stramonium) or extra axillary<br />

scorpioid cyme called rhipidium (fan shaped cyme) as in S. nigrum or<br />

helicoid cyme as in S. tuberosum or umbellate cyme as in Withania<br />

somnifera.<br />

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