Arisaema candidissimum, the white-spathed jack in the pulpit, is a herbaceous perennial in the Araceae that flowers in the UK between May and July. Native to western China, it suits sheltered, shaded corners where soil stays moist. Plant in well-drained, humus-rich soil that is neutral to slightly acidic and position it on a north or east-facing aspect. Wear gloves and eye protection when handling, as the plant is harmful if eaten and can irritate skin and eyes.

White-spathed jack in the pulpit (Arisaema candidissimum) flowers from May to July and prefers sheltered, shaded, humus-rich sites in the UK.

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

Arisaema is a large and diverse genus of the flowering plant family Araceae. The largest concentration of species is in China and Japan, with other species native to other parts of southern Asia as well as eastern and central Africa, Mexico and eastern North America.

Arisaema candidissimum

White-spathed jack in the pulpit | Arisaema candidissimum

Arisaema jinshajiangense is a columnar upright member of the Araceae with deciduous foliage. It flowers in the UK from May to July. The plant prefers partial shade and a sheltered position on moist but well-drained loam or sandy soil with an acid to neutral pH. It is rated H4 for UK hardiness, suitable for average winter conditions.

Arisaema jinshajiangense suits sheltered, north- to west-facing partial shade and flowers in the UK from May to July.

Arisaema jinshajiangense

Arisaema jinshajiangense | Columnar Arisaema for Shade

Arisaema ringens f. glaucescens is an Arisaema in the Araceae with a columnar upright habit and deciduous foliage. It flowers from May to July. Best grown in partial shade in moist but well-drained loam or sandy soil of neutral to acid pH. Position in a north, east or west-facing sheltered spot where it can be used beneath shrubs or in cottage-style borders.

Japanese Cobra Lily (Arisaema ringens f. glaucescens) is a columnar, deciduous arum for sheltered, partially shaded spots that flowers May to July.