Rhododendron kiyosumense

Flower name
Rhododendron kiyosumense
Scientific name
Rhododendron kiyosumense
Alias三葉躑躅, イワツツジ, 岩躑躅, 清澄三葉躑躅
Place of originendemic to Japan
Place of floweringGarden, Botanical Gardens, Low mountains
Flowering seasonApril, May

What is Rhododendron kiyosumense

Rhododendron kiyosumense (scientific name: Rhododendron kiyosumense) is a deciduous broad-leaved shrub in the family Ericaceae, found on Kiyosumiyama in Kamogawa City, Chiba Prefecture. It is also known as "iwa-tsutsuji" (meaning "rock azalea") because it grows wild on rocks in the mountains on the Pacific side of Kanagawa, Shizuoka, and Mie prefectures. It is a species of 'Rhododendron dilatatum' with three leaves arranged in a ring on each branch. What is the difference between R. dilatatum and R. kiyosumense?
R. kiyosumense is distributed in parts of Kanagawa, Shizuoka, and Mie, blooms from April to May, has dark reddish purple (dark color) petals, 10 stamens, the petiole is not persistent, and only one flower is produced at the tip of a branch.
R. dilatatum is distributed in Kanto and Chubu regions, blooms from March to April, petal color reddish purple (light color), 5 stamens, petiole persistent, 2 to 3 flowers bloom at the branch tips.

Common name: Rhododendron kiyosumense, or Kiyosumi-tsuba azalea, scientific name: Rhododendron kiyosumense, height: 200-300 cm, Place of origin: Kiyosumiyama in Kamogawa City, Chiba Prefecture, Environment: thicket; Life form: deciduous broad-leaved shrub; Leaf shape: rhomboidal, broadly ovate; Leaf color: green; Inflorescence: 3-lobed; Leaf margin: entire; Flowering season: April to May; Flower diameter: 3-4 cm; Corolla shape: funnel-shaped with 5 lobes; Flower color: dark reddish purple; Stamens: 1; Number of stamens: 10; Fruit type: capsule; Use: garden tree, potted plant.