Refers specifically to Rhododendron indicum, a type of azalea that blooms in late spring (around May). The reading さつき is the standard modern name; とけんか is a rare Sino-Japanese reading.
See also: 皐月
Satsuki azaleas are blooming in the garden.
Satsuki azaleas bloom around May.
Rare kanji spelling for さつき (satsuki azalea). The reading とけんか is also possible but very uncommon.
Common katakana spelling for the plant name, often used in botanical contexts.
The name サツキ comes from 皐月 (さつき), the old Japanese name for the fifth month of the lunar calendar, when this azalea typically blooms. The kanji 杜鵑花 is a Chinese-derived spelling, but its exact historical adoption is uncertain.