This description is based on the book Sugawara No Michizane and the Early Heian Court by Robert Borgen page 69.
When Michizane celebrated his coming of age, his mother wrote the following poem
tsuki no katsura mo
ie no kaze o mo
The cassia tree
On the far off moon
May you vigorously maintain
Our family tradition.
Breaking a branch of the cassia said to grow on the moon was a conventional metaphor, taken from Chinese literature, for success in the civil service examinations. Thus, the poem expressed his mother’s hope that Michizane would study diligently and one day pass the examinations. Both his father and grandfather had passed them, and she wanted him to continue what had become a family tradition.
Another translation is from A Waka Anthology: Grasses of Remembrance (2 v.) By Edwin A. Cranston page 2376.
Let me have my wish
Keep you our house-wind blowing
With so steady a force
That from the high heaven’s moon
A cassia branch breaks off
According to Chinese legend, a katsura (laurel or Judas tree) five-hundred jou (1500 m) in height grows on the moon.
There is a Chinese expression which in Japanese is “tsuki no katsura wo oru” “to break off a branch of the moon laurel” meaning “to succeed in the official examination”.
This is an original work of art by Master Japanese Calligrapher Eri Takase. The art comes with foam core backing and is ready to frame.