Q 01/05

What is the scientific name of the common sunflower?

A) Helianthus annuus

B) Heliotropium arborescens

C) Rudbeckia hirta

D) Calendula officinalis

Answer · why

A) Helianthus annuus

The genus name is Greek for sun-flower and the species name is Latin for yearly, since it lives and dies in a single season.

Q 02/05

The genus name Helianthus is built from two Ancient Greek words. What do they mean?

A) Gold and petal

B) Seed and oil

C) Tall and yellow

D) Sun and blossom

Answer · why

D) Sun and blossom

The same 'helios' root gives us helium, first detected in the light of the sun before it was found on Earth.

Q 03/05

Sunflowers belong to which plant family, one of the largest on Earth with more than 32,000 species?

A) The roses

B) The lilies

C) The peas

D) The daisies

Answer · why

D) The daisies

Lettuce, dandelions, artichokes and chrysanthemums are all cousins; together the family makes up about a tenth of all flowering plants.

Q 04/05

What is often called a sunflower's 'flower' is really what?

A) A single flower with hundreds of petals

B) A seed pod that opens early

C) A cluster of modified leaves

D) A head made of many tiny flowers

Answer · why

D) A head made of many tiny flowers

The outer 'petals' are ray florets and the dark centre is packed with disc florets, each one a complete five-petalled flower that can produce a seed.

Q 05/05

Which sunflowers actually track the sun across the sky during the day?

A) Only the mature flowering heads

B) None; the tracking is a myth

C) All sunflowers, at every stage

D) Only immature buds and young plants

Answer · why

D) Only immature buds and young plants

Once the stalk stops growing the head locks into place, and it usually ends up facing east to catch the morning warmth.