flowers in a vase or lapel
Refers to cut flowers arranged in a vase or worn as a decoration on clothing, such as a boutonniere.
I decorated the table with flowers in a vase.
新郎のスーツには白い挿し花がついていた。
The groom's suit had a white boutonniere.
Compound of 挿し (sashi, 'inserting') + 花 (hana, 'flower'). The reading さしばな is a rendaku form of はな.