Helianthus annus (Sunflower) Family Astraceae Compositae

Astraceae is the largest family of angiosperms comprising of 950 Genera and approximately 20,000 species. Most common genera are Helianthus annus (sunflower), Sonchus asper (dodak), Carthamus tinctorius (kusum), Artemesia absinthium (afsantin), Lactuca sativa (salad), Ageratum conyzoides, Tagetes (gainda), Zinnia, Xanthium, etc. The members of the family are worldwide in distribution.

Helianthus annus (Sunflower)

Family Astraceae Compositae Helianthus annus (Sunflower)

Distingushing Features Helianthus annus (sunflower)

Herb, with simple alternate leaves, flower is capitula, may be differentiated into ray and disc florets, actinomorphic or zygomorphic, epigynous, calyx represented by pappus, corolla gamopetalous of five lobes, stamen 5, epipetalous, gynoecium bicarpellary, syncarpous, ovary inferior, unilocular with a single basal ovule, fruit a cypsela.

Helianthus annus (Sunflower)

Habit

An annual herb cultivated for its seeds that yield oil rich in proteins and vitamins A, D and E. This oil is used for cooking and in salads.

Root

Tap Root, Branched, Fibrous.

Stem

The Stem of Helianthus annus is Erect, herbaceous above and woody below, cylindrical, glabrous, branched.

Leaf

Cauline and ramal, exstipulate, simple, ovate, petiolate, reticulate unicostate, Leaf margin: serrate.

Inflorescence

In Helianthus annus (sunflower) the inflorescence is Racemose A heterogamous capitulum comprising of ray and disc florets. Involucre comprising of several whorls of bracts is present at the base of the inflorescence.

Ray Florets

Bracteate, sessile, incomplete, irregular, zygomorphic, ligulate, Epigynouse

Calyx

Either absent or represented by 2 – 3 scales, Superior.

Corolla

Yellow, gamopetalous, 2 – 5 petals, ligulate, superior.

Androecium

Absent.

Gynoecium

Absent.

Floral Formula K0 or scales C(2-5)  A0  G(0)

Disc Floret

Bracteate, sessile, incomplete, regular, tubular, actinomorphic, bisexual, epigynous.

Calyx

Either absent or represented by 2 – 3 scales, superior.

Corolla

5 petals, gamopetalous, tubular, toothed, teeth represent number of petals, superior.

Androecium

5 stamens, Epipetalous, Syngenesious, Superior.

Gynoecium

Bicarpellary, Syncarpous, Ovary: inferior and uniclocular with a single basal ovule, Placentation: basal, Stigma: bifid.

Floral Structure of Helianthus annus (Sunflower)

Floral Diagram of Helianthus annus (Sunflower)

Economic importance of Family Helianthus annus (Sunflower)

Food

Root and leaves of cichory (Cichorium intybus), leaves of Icttuce (Lactuca sativa-salad) and (Cynara cardunculus-cardoon) and roots of Jerusalem artichoke (Helianthus tuberosus) are used as food. Roots of cichory are often roasted and mixed with coffee. Similarly roots of Dandelion are also used to adulterate coffee,

Dye

Flower of Carthamus yield a yellow dye

Medicinal

Certain species of Artemisia are used in making beer. Seeds of Centrathem are used for round worms and insecticides.

Oil

Sunflower yield oil which is used for cooking purposes.

Poisons

A number of genera of the family like rag weeds and golden rods are cause of hay fever and other diseases.

Ornamental Plant

Dahlias, Asters etc. Are cultivated for ornamental purposes.

Leave a Reply

Your email address will not be published. Required fields are marked *

*

Distributed by name369.com