japonica – refers to native region of Japan

Native range: South Korea, Japan

Leaves:

• alternate
• 7-9 lobed (rounded sinuses)
• broadly cordate base
• serrate margin
• shiny dark green
• 6-14” wide
• ~wider than long
• distinct u-shaped leaf scar on branch
• extremely long petioles (4-12”)

Flowers:

• inflorescence – umbels 1-1.5” across
• 5-parted
• white
• flowers in fall

Fruit:

• berries
• round, green turning into black
• ripens in winter

Other characteristics:

• evergreen shrub to 15 ft.
• many large stems

Relevant info:

• Japanese name: Yatsude, which may refer to many-fingered-hand shape of leaf
• introduced in Eastern China
• formerly classified as Aralia by Swedish botanist Carl Thunberg (1748-1828), a pupil of Linneas
• in same family as English ivy

Ecology & Adaptations:

• native coastal woodlands from South Korea to Japan to Nansei-shoto (islands between Japan and Taiwan)
• very shade tolerant:
  • evergreen leaves photosynthesize all year
  • able to acclimate to different light conditions by altering its anatomical and physiological characteristics (e.g., photosynthetic rate, light compensation point & light saturation point (which increase in high light) & chlorophyll content (which increases in low light)
  • in full sun, plant experiences mid-day depression in photosynthesis as stomata close to avoid water loss
  • leaf size and thickness decrease under low light, so acclimation to low light limits biomass production
• cold tolerant and frost resistant (to -5ºC) – due to increase in protective, antioxidant enzymes that prevent cellular damage
• vegetative reproduction – produces suckers from trunk base
• pollination:
  • by insects, especially wasps and flies
  • fall timing decreases competition for pollinators
• seed dispersal – by birds consuming fruit
• herbivore protection – toxic compounds in flower buds, flowers, mature fruits, and leaves