Asteraceae Lecture Exam

Question 1

How big is this family and where can it be found (and not found)?

Answer 1

found worldwide, except antarctica

Question 2

What genus, with two species native to MN, was noted to exhibit only disk flowers?

Answer 2

Echinacea
-E. angustifolia and E. pallida are the MN native spp.

Question 3

What is one of our most ubiquitous Asteraceae species seen in MN?

Answer 3

Symphyotrichum spp. (Aster)
-18 sp. native to MN

Question 4

What was the genus noted for being responsible for up to 1/2 of the pollen allergies in N.A.?

Answer 4

Ambrosia (Ragweed)
-can produce 1 billion grains of pollen/season

Question 5

What would be your concise family description for the Asteraceae composite flower?

Answer 5

-florets in a compact head on a common receptacle
-often and outer whorl of ray flowers with an inner dome of disk flowers
-subtended by phyllaries (basically bud scales)

Question 6

What is a pappus?

Answer 6

modified calyx that surrounds the base of the corolla on an individual ray or disk floret

Question 7

What is the compound derived from Artemisia that has been used to treat parasite infections, including malaria?

Answer 7

sesquiterpene compounds

Question 8

What is the risk associated with using pyrethrums as an insecticide?

Answer 8

it is highly toxic to fish!

Question 9

Name a food producing member of the Asteraceae family.

Answer 9

Helianthus annuus (sunflower)

Question 10

How would you characterize the ornamental members of the family in terms of their garden use?

Answer 10

many are invasive or have ruderal spp. (colonize disturbed areas)

Question 11

Are knapweeds good or bad?

Answer 11

Many are allelopathic (produce toxins in roots that impede the growth of other plants)
-pappus and rhizomatous, so it spreads readily
-however, great for pollinators and refuge for insects