The most common and most likely answer to this crossword clue is the 10 letter word SNEEZEWEED
S
N
E
E
Z
E
W
E
E
D
Buddy explains!
The straight part
We know that "helenium" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case helenium = sneezeweed.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does SNEEZEWEED mean?
SNEEZEWEED noun- A plant of the genus Helenium, especially Helenium autumnale.
- A plant of the genus Centipeda; either of the species Centipeda cunninghami or Centipeda minima, which induce sneezing and are known as a folk remedy for colds and allergic reactions.