Thistle Identification Referee 2017
Welcome to the Thistle Identification Referee. The purpose of the referee is to review morphological characters that are useful for identification of thistle and knapweed fruits, as well as review useful resources for making decisions on identification and classification of species as noxious weed seeds. Using the Identification Guide for Some Common and Noxious Thistle and Knapweed Fruits (Meyer 2017) and other references of your choosing, please answer the questions below (most are multiple choice).
Use the last page of this document as your answer sheet for the questions. Please send your answer sheet to Deborah Meyer via email ([email protected]) by May 26, 2017. Be sure to fill in your name, lab name, and email address on the answer sheet to receive CE credit.
1. In the Asteraceae, the pappus represents this floral structure: a. Modified stigma b. Modified corolla c. Modified calyx d. Modified perianth
2. Which of the following species has an epappose fruit? a. Centaurea calcitrapa b. Cirsium vulgare c. Onopordum acaulon d. Cynara cardunculus
3. Which of the following genera has a pappus comprised of plumose bristles? a. Centaurea b. Carduus c. Silybum d. Cirsium
4. Which of the following species has the largest fruits? a. Cirsium arvense b. Cirsium japonicum c. Cirsium undulatum d. Cirsium vulgare
5. Which of the following species has a pappus that hides the style base? a. Volutaria muricata b. Mantisalca salmantica c. Centaurea solstitialis d. Crupina vulgaris
6. Which of the following species is classified as a noxious weed seed somewhere in the United States? a. Amberboa moschata b. Centaurea cineraria c. Centaurea cyanus d. Mantisalca salmantica
7. What resource did you use to answer question #6?
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8. To what region of the world is Mantisalca salmantica native? a. South Western United States b. Mediterranean Region c. Southern Africa d. Pacific Northwestern United States
9. What resource did you use to answer question #8?
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11
13
10 12
14
Please use the above drawings to answer the questions 10 through 14:
10. The outer layer of this structure is a. Seed coat b. Testa c. Pericarp d. Perianth
11. What is the name of this structure? a. Hilum b. Point of fruit attachment c. Stigma d. Style base
12. What is the name of this area of the fruit in Centaurea? a. Pappus ring b. Scar rim c. Elaiosome ring d. Apical rim
13. This structure is: a. Attractive to ants b. Helpful to fruit dispersal c. Persistent on all fruits in Centaurea solstitialis d. Attached to the base of the inferior ovary
14. What is the name of this structure? a. Hilum b. Point of fruit attachment c. Stigma d. Style base
15. The margin of this apical rim can be described as: a. Crenulate b. Dentate c. Lanceolate d. Oblanceolate
16. What is the structure indicated by the arrow?
a. Apical rim b. Elaiosome c. Hilum d. Style base
17. What species has an inner pappus whorl consisting of a single broad scale? a. Carthamus lanatus b. Centaurea benedicta c. Mantisalca salmantica d. Volutaria muricata
18. What species is this?
a. Carthamus oxycantha b. Carthamus tinctorius c. Centaurea jacea d. Rhaponticum repens
19. What species is this?
a. Carthamus oxycantha b. Carthamus tinctorius c. Centaurea jacea d. Rhaponticum repens
20. The species from question #19 is: a. Pappose b. Epappose
21. What species is the contaminant in this white clover sample? a. Centaurea diffusa b. Centaurea solstitialis c. Centaurea stoebe d. Centaurea virgata
22. What one character did you find most useful to make your species identification for question #21?
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24
23
Use the photo above of a bird seed mix to answer questions 23 through 25.
23. Name the species of the object circled and labeled as 23 in this photo?
a. Centaurea diffusa b. Centaurea jacea c. Centaurea melitensis d. Centaurea solstitialis
24. In what state is the object circled and labeled as 24 classified as a noxious weed seed?
a. Nebraska b. Nevada c. New Jersey d. New Mexico e. North Carolina f. North Dakota
25. Name one other genus in the Asteraceae shown in this photo that is considered a noxious weed seed in California.
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A B
Fuzzy photos are sometimes all you receive when asked to make seed identification determinations. Using the sadly out of focus photo above to answer questions 26 and 27.
26. What species is represented by the specimen labeled A? a. Carduus acanthoides b. Carduus nutans c. Carduus pycnocephalus d. Cirsium arvense e. Cirsium undulatum
27. What species is represented by the specimen labeled B? a. Carduus acanthoides b. Carduus nutans c. Carduus pycnocephalus d. Cirsium arvense e. Cirsium undulatum
28. According to Vol. 3 of the AOSA Rules, which name listed below is the currently accepted scientific name for Russian knapweed? a. Acroptilon repens b. Centaurea repens c. Centaurea picris d. Rhaponticum repens
Please return your answer sheet to Deborah Meyer via email at [email protected] by May 26, 2017.
Required information to receive continuing education credit for referee participation:
Participant Name (please print) ______
Lab Name ______
Email Address ______
Corresponding letter answer (example: a) or written answer for questions 7, 9, 22, & 25 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28