rose of Sharon; Hibiscus syriacus
Refers to the flowering shrub Hibiscus syriacus. Cross-referenced with 木槿 (むくげ), which is the more common name for this plant. キハチス is a less common synonym, possibly dialectal or older.
See also: ムクゲ
The rose of Sharon blooms beautifully in summer.
I planted a rose of Sharon in the garden.
Kanji form is rare; the reading きはちす is not standard for this kanji, which is usually read もくれん (magnolia). This is likely an irregular or archaic usage.
The origin of キハチス is uncertain. It may be an older or dialectal name for the plant, while むくげ (木槿) is the standard term.