Arisaema ringens

Plant of the Month June 2023

GENERAL INFORMATION: 

I was fascinated by “Jack-in-the-Pulpits” as a child in England. Arum maculatum grew in our woods. We also called it Lords-and-Ladies and Cuckoo-Pint. Was there something improper about the plant? I recently learned “pint” was a shortening of “pintle” (penis!) My Grandmother had a scary, smelly Voodoo-Lily (Amorphophallus konjak) in her garden. Now I find Arisaema triphyllum growing in our Ontario woodlands.

All three are among 140 genera of the Aroid family, or Araceae. These are characterized by a large, frequently colourful, upright to curled over bract called a spathe (pulpit). This encloses the spadix (Jack), which is an upright thick stalk bearing numerous male and/or female flowers. When teaching, I liked to show teen-aged students a small Arisaema triphyllum and tell them it was a male plant. It would be female the next year if it grew big and strong enough! Seed production might exhaust it and it would return to being a male plant! (Paradioecious, changing back and forth.)

Synonym: Arisaema praecox. Arisaema sieboldii. Arum ringens.

Common Name: Japanese Cobra Lily.

Cultivars:

    Arisaema ringens ‘Black Mamba’ – dark purple pseudostems.

    Arisaema ringens var. glaucescens – green spathe.

Arisaema ringens.

Life Cycle: Perennial, growing from disc shaped tubers. 

Size: to 0.5m x 0.5m.

Bloom Time: The plant usually emerges during the first week of May in Toronto. The inflorescences open soon after, in mid May to June.

Arisaema ringens early May.

Leaves: A mottled purple pseudostem bears 2 long lasting glossy trifoliate leaves. The 3 leaflets are oval to elliptical and about 15 cm long. The leaves die down in late summer if no seeds develop.

Arisaema ringens - leaves.

Flower Colour & Size: Long lasting Arum flowers. The thick spathe, striped in green, purple and white curls forward and down, looking like the head of a cobra.

Arisaema ringens – four inflorescences.

The glimpse of the shiny purple interior gives the impression of 2 eyes. The creamy coloured spadix is hidden inside. The tiny flowers are usually male or female with an occasional hermaphrodite plant.

                      Arisaema ringens – closeup.                                  Arisaema ringens – female.

Fruit: Red berries in fall, if male and female plants present. I have had berries once which did not develop.

Range: China, Japan, Korea.

Habitat: Lowland woods.

CULTIVATION: 

Plant: Plant dormant tubers in fall, at least 10 cm deep with a handful of gravel mixed below.

Light: Part to full shade.

Soil: Humus rich, well drained soil. Avoid heavy clay.

Water: Medium moisture to wet soil, though my plants dry out frequently.

USDA Hardiness: Zones 5-9.

Companion planting: Woodland plants – Ferns, Hosta, Stylophorum diphyllum (wood-poppy), and if light shade,  Hakonechloa macra 'Aureola' (Japanese forest grass). 

Propagation: Dig plant in fall and separate tubers - replant. From seed: Remove fleshy coat. (Use gloves.) Gently scarify. Soak in hand-hot water for 24 hours. Plant and keep at 20°C. Let seedlings grow for as long as possible, feeding with an all purpose fertilizer. Keep at 4°C over winter.

Problems:  None noted. The plant is poisonous.

References:

https://www.missouribotanicalgarden.org/PlantFinder

https://onrockgarden.com/index.php/germination-guide

https://pfaf.org/user/Plant.aspx?LatinName=Arisaema+ringens

https://en.wikipedia.org/wiki/Araceae

https://www.plantdelights.com/blogs/articles/arisaema-arisaema-arisaema

Text and images supplied by Anna Leggatt (Toronto Master Gardener)