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| Family Asteraceae |
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| Division: Angiospermae |
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| Class: Dicotyledonae |
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| Subclass: Gamopetalae |
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| Series: Inferae |
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| Order: Asterales |
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| Family: Asteraceae (=compositae) |
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| 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. |
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 Habit: Mostly annual herbs, rarely shrubs and trees. |
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| fig. 27.38 Habit, L.S. of inflorescence and florets |
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 Root: Taproot system, branched. |
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 Stem: Herbaceous or woody, erect, branched. |
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 Leaves: Simple, alternate or opposite, exstipulate, petiolate, hairy, reticulate venation. |
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 Inflorescence: Head or capitulum, terminal or axillary. Florets surrounded by an involucre of bracts. |
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 Flower: Bisexual, pentamerous, heterochlamydeous, epigynous. |
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 Ray florets: Towards periphery, sessile, bracteate, pistillate or neutral, zygomorphic, ligulate. |
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 Calyx: Absent or hairy pappus, or scaly persistent. |
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 Corolla: Petals 5, polypetalous, ligulate. |
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 Androecium: Absent. |
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 Gynoecium: Bicarpellary, syncarpous, unilocular, one ovule, the locule, basal placentation, style narrow, stigma branched, ovary inferior. |
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 Disc Florets: Towards the centre, bracteate, bisexual, actinomorphic, tubular, epigynous. |
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 Calyx: Absent or modified into pappus. |
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 Corolla: Sepals 5, Gamosepalous, tubular. |
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 Androecium: Stamens 2, epipetalous, syngenesious dithecous. |
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 Gynoecium: Bicarpellary, Syncarpous, unilocular, one ovule, on basal placentation style single, stigma bifid. |
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 Neutral florets: Both androecium and gynoecium are absent. Remaining characters similar. |
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 Fruit: Cypsela. |
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 Seed: Non-endospermic. |
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 Floral formula: |
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| Ray florets |
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| Disc florets |
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| Neutral florets |
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| fig. 27.39 Types of florets, their L.S. floral parts, floral diagram and floral formula |
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| Edible |
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| 1. Lactuca sativa (Lettuce) |
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| 2. Elephantopus - Leaves edible |
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| 3. Helianthus tuberosum - tubers edible, seeds yield oil |
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| Medicinal |
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| 1. Carathamus tinctorius - Oil used for treating injuries |
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| 2. Cynara scolymus - flowers are used for treating diabetes |
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| 3. Artinesia obisynthium - yields santonin used for treating worms |
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| 4. Xanthium stramonium - leaves used for treating tooth ache |
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| Ornamental |
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| 1. Helianthus annus sunflower yields oil |
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| 2. Tagetus erectus - marigold |
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| 3. Chrysanthemum species |
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| 4. Cosmos species |
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| 5. Veronica species |
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| 6. Zinnia species |
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| fig. 27.40 Examples of Family Asteraceae |
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