Liu in Chinese / Japanese...

柳 is the Chinese, old Korean Hanja, and Japanese Kanji for willow (as in willow tree).

In ancient Chinese astronomy/astrology, this can refer to the “Willow” constellation (one of the 28 mansions).

If you want to get scientific, this can refer to any tree of the genus Salix including the weeping willow (Salix babylonica).

Notes:
In Chinese, this can be the surname Liu.
In Japanese, it can be the surname Yanagi. It can also be pronounced other ways for different rare surnames. Some Japanese use this as a female given name.
In Korean, this can be the surname Yu, though most of the time it’s pronounced ryu in Korean.

六 is the number 6 in Chinese, Korean Hanja, and Japanese Kanji. I have no idea why you would want this as a calligraphy wall scroll, but hundreds of visitors search for this number.

In Japanese, this character can be pronounced differently depending on context. It can be ryu, roku, mu, and a few others when combined with other Kanji.

There's just one way to pronounce this in Chinese. Korean also has just one pronunciation.

Also written 陸 or 陆 as an anti-fraud banker’s numeral.