Plant of the Month for July, 2017

Arisaema thunbergii ssp urashima header
Arisaema thunbergii ssp. urashima

 (air-uh-see-muh  thun-BERG-ee-eye)

General Information:

Arisaema thunbergii ssp. urashima is a great aroid that adds some excitement to the garden. Known as the dominatrix jack-in-the-pulpit it appears in late spring and is gone by late summer. Its special feature is a long, dark purple, whip-like spadix that can reach 45 cm long, in true dominatrix fashion.

Arisaema thunbergii ssp urashima main

Arisaema thunbergii ssp. urashima by Robert Pavlis

Unlike many of its cousins, this denizen of the woods is easy to grow. Over time it makes offshoots that can be separated from the parent plant. It can also be grown from seed but may take 3-5 years to flower.

Fertilized flowers will produce red berries that mature in fall after the leaves have faded. All parts of the plant contain calcium oxalate and are poisonous.

Arisaema thunbergii ssp urashima closeup

Arisaema thunbergii ssp. urashima by Robert Pavlis

The subspecies urashima, is similar to the species, but is shorter growing to just 45 cm tall, and has 11-15 broad leaflets instead of 9-17 narrow ones.

Arisaema thunbergii ssp urashima top view

Arisaema thunbergii ssp. urashima by Robert Pavlis

Arisaema thunbergii ssp urashima spadix closeup

Arisaema thunbergii ssp. urashima by Robert Pavlis

Life Cycle: perennial

Height: 45cm (18in)

Bloom Time: late spring

Natural Range: Japan

Habitat: woodlands

Synonyms:  Arisaema urashima, Arisaema thnbergii, Flagellarisaema urashima,


Light: part shade to shade

Soil: humus-rich, well drained

Water: medium to wet

USDA Hardiness Zone: 5 - 9

Propagation: seed, division

Seedex availability (ORG&HPS annual Seed Exchange): rarely

Robert Pavlis