Arisaema tortuosum

The Arisaema tortuosum is a strange tuberous perennial native to China. In early summer, a flower head emerges between two large arched leaves, resembling a "snake's head" in apple green colour, similar to our woodland arums but taller and more spectacular. As an understory plant, it thrives in cool environments and humus-rich, well-drained soils. Despite its exotic appearance, it is easy to cultivate and adapt well to moderately warm climates.

Arisaema tortuosum belongs to the Araceae family, just like Zantedeschia (white arums) and the native cuckoo pint of our forests. It is found in southwest China and neighbouring countries (Bhutan, Nepal), in woodlands, on rocky slopes, and along stream banks at altitudes between 1300 and 2900 metres (4265 and 9514 feet). It is a perennial with a flat tuberous stump, which may resemble cyclamen tubers but with a less smooth surface. In late spring, this tuber produces two bright green leaves, called "pedate" leaves, shaped like a curved bicycle handlebar with 7-9 lobes. They are carried on long rigid petioles, nested within each other, forming an erect stem-like structure. Under suitable conditions and depending on the plant's origin, the entire structure can reach a height of 60 cm (24in) to 1.20 m (4ft). In early summer, shortly after, a curious cornet-like flowering structure appears between the leaves. Like most plants in this botanical family, it is a flower head composed of a green apple-coloured 10 cm (4in) spathe surrounding a central stalk (spadix) that contains tiny flowers. In Arisaema tortuosum, this purple or green spadix curves upwards and can exceed 20 to 30 cm (8 to 12in) in length (which also gives it its Latin name, meaning "twisted, tortuous"). This cornet, like all Arisaema plants, can also resemble a snake's head with a protruding tongue, hence their common name, "cobra plant". Sometimes, in the presence of multiple plants, small berries form and can disperse the plant through self-sowing. As soon as fruiting is complete, the entire plant enters a dormant phase and completely disappears until the following spring.

Arisaema tortuosum, despite its exotic appearance, is perfectly hardy (down to at least -15°C (5°F)) and easy to grow, so it poses no problem even in cool climates. However, it does not thrive in hot and dry environments, which restricts its size and causes it to enter dormancy quickly. Provide a shady or semi-shady location in good, rich, humus-rich garden soil that is not too heavy. Adding dead leaves to the plant each year can be beneficial as it provides a layer of mulch. It's best to avoid planting in windy locations as it can cause the stem to bend or break. However, under normal conditions, staking is not required, mainly when other low-growing perennials or bushes surround the plant. Since the leaves emerge late, mark the plant's location to avoid accidentally digging it up at the beginning of the season.

As the cobra plant disappears in summer, you can place it under deciduous trees, which will only start drawing water from the soil once it has gone dormant. Combine it with other exotic-looking perennials to create a stunning, contrasting, yet perfectly hardy border: Kirengeshoma palmata, Boehmeria biloba, Corydalis 'Porcelain Blue', Hosta 'Halcyon', or even Decaisnea fargesii among the bushes, will provide excellent company to this underrated perennial.