Rhododendron metternichii
A species of rhododendron native to Japan; the name is usually written in katakana.
Rhododendron metternichii is an evergreen shrub that grows wild in alpine regions.
シャクナゲ is the general term for rhododendron; ホンシャクナゲ refers specifically to Rhododendron metternichii.
Katakana spelling is standard for this plant name; the kanji form 本石楠花 is rare.
Kanji form is rarely used; the plant is almost always written in kana.
The name is a compound of 本 (hon, 'true' or 'main') and シャクナゲ (shakunage, 'rhododendron'), distinguishing this species from other rhododendrons.