X  MARKS THE SPOT I
Credit Will Shortz in The Puzzlemaster Presents

The answers to the clues below will each end in the letter  X . These answers, in turn, will share a common characteristic. Can you determine what it is?

1. Mythological river of the underworld
2. Last name of brothers Groucho, Chico, and Harpo
3. Government levy
4. Persuade
5. Container or seat
6. Loose and permissive, as rules
7. T.  or Oedipus
8. Plant with colorful flowers
9. Gold depository Fort
10. New York borough
11. Body builders do this in contests

Answers to the first part:

1. Styx
2. Marx
3. Tax
4. Coax
5. Box
6. Lax
7. Rex
8. Phlox
9. Knox
10. Bronx
11. Flex

Answer to second part:

Each answer word has a homophone.

1. Styx - sticks
2. Marx - marks
3. Tax - tacks
4. Coax - Cokes
5. Box - Bach's
6. Lax - lacks
7. Rex - wrecks
8. Phlox - flocks
9. Knox - knocks
10. Bronx - broncs
11. Flex - flecks