The most common and most likely answer to this crossword clue is the 5 letter word CYCAD
C
Y
C
A
D
More clues leading to the result CYCAD
Buddy explains!

The straight part
We know that "Gymnosperm" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case gymnosperm = cycad.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 CYCAD mean?
CYCAD noun- Any plant of the division Cycadophyta, having a stout and woody trunk with a crown of large, hard and stiff, evergreen leaves.