The rhythm of this poem is definitely iambic. What do we find, however, at the start of the fourth line below?
He did not wear his scarlet coat,
For blood and wine are red,
And blood and wine were on his hands
*
* / | *
/ | * /
[possibly even: * * / | / * | * /
When they found him with the dead,
The poor dead woman whom he loved,
And murdered in her bed.
--Oscar Wilde