distribution, habit vegetative characters floral characters

1. Family Asteraceae
• The family contains about 950 genera and
probably 20000 species.
• Distribution:
• Cosmopolitan in distribution.
• Vegetative characters:
• Habit: Herbs, shrubs, very rarely climbers (e.g.
Mikania scandens) and trees (e.g. Lachanodes
arborea). Many plants possess milky juice
while in others the juice is watery and bitter.

2. Mikania scandens

3. Lachanodes arborea

4. • Root: Tap root; branched. In some cases
tuberously thickened e.g. H. tuberosus
• Stem: soft, some times woody; usually hairy;
erect.
• Leaf: simple or compound; Alternate, sometime
opposite and rarely whorled, exstipulate;
petiolate, some time scales leaves.
• Floral characters:
• Inflorescence: Racemose: head or capitulum
• Flower: flowers of the capitulum, i.e. florets may
be hermaphrodite, unisexual or neutor;
pentamerous; actinomorphic or zygomorphic,
epigynous.

5. H. tuberosus

6. • Disc floret: sessile, regular, actinomorphic ;
complete; hermaphrodite; bracteate; epigynous
• Calyx: Rudimentary or entirely absent, sometimes
modified into a large number of bristles or hair
like structure called pappus.
• Corolla: 5; gamopetalous; tubular; 5 lobed;
actinomorphic.
• Androecium: 5; epipetalous; alternate with
corolla lobes.
• Gynoecium: 2 carpels; syncarpous; ovary inferior,
placentation basal.

7. • Ray floret:
• Sessile, zygomorphic; irregular
• Calyx: represented by pappus or absent.
• Corolla: 5; gamopetalous; bilabiate
• Androecium: Absent
• Gynoecium: absent
• Fruit: Cypsella

9. Floral formula and floral diagram

10. Important members:
Helianthus annus

11. Lactuca sativa

12. Sonchus asper

13. Chrysenthemum indicum

14. Taraxicum officinale

15. Artemisia indica

16. Calendula officinalis

17. Tagetus erecta

18. • Economic Importance of Asteraceae:
• 1. Food:
• Leaves of Lactuca sativa are used as salad. The
roots of Helianthus tuberosus are edible.
• 2. Oil:
• The seeds of Helianthus and Artemisia yield oil.
• 4. Rubber:
• It is obtained from Solidago laevenworthii and
Taraxacum.
• 5. Insecticide:
• The capitula of Chrysanthemum roseum and C.
cinerriefolium are dried, powdered and used as
insecticide.

19. • Medicinal:
• Solidago used in dropsy.
• Artemisia yields santonin which is used as
vermifuge.
• The roots of Taraxacum used in bowel disorders.
• The juice of Emillia sonchifolia leaves has cooling
effect and is used in eye inflammation and also
for night blindness.
• Eclipta alba used as tonic in spleen enlargement.
• Centipeda orbicularis is used in cold and
toothache.

20. • Ornamental:
• Zinnia, Dahila, Cosmos, Chrysanthemum,
Calendula, Helichrysium, Aster, Helianthus etc.
are well known garden plants.
• 7. Weeds:
• Xanthium, Blumea, Sonchus, Vernonia are the
common weeds.