But whatsoever else it may secrete,
Its flowers' distilled honey is so sweet
It makes the butterflies intemperate.
There is no slumber in its juice for them.
One knocks another off from where he clings.
They knock the dyestuff off each other's wings -
With thirst on hunger to the point of lust.
They raise in their intemperance a cloud
Of mingled butterfly and flower dust
That hangs perceptibly above the scene.
In being sweet to these ephemerals
The sober weed has managed to contrive
In our three hundred days and sixty five
One day too sweet for beings to survive.
Many shall come away as struggle worn
And spent and dusted off of their regalia
To which at daybreak they were freshly born

 an alluring resource can stir creatures to uncouth behavior, especially when there’s a high concentration of that creature where the alluring resource is available. what seems sweet leads to excess and ugliness. 
 It seems that the time when the milkweed is in bloom or whatever (i.e. when the milkweed is attractive to the butterflies) is a very short time. The butterflies all rush to get their fill – no time to think about their neighbors or anything other than the honey.
Pod of the Milkweed