Botanical name: Arisaema ringens
Family Name: Araceae - The Arum family which includes many lilies.
Common name: 'Cobra Lily'- From the shape of the flower.
Origins: From China and Korea.
A bulbous plant with a tuber which is shaped like a flattened potato, smooth on the lower side and having pointed buds on the upper side. Tuber from about 5cm across will flower, and larger corms will sometimes produce two or three flowering shoots.
In the spring the plant comes into growth from the buds on the top of the tubers which develop a skirt of roots which grow out over the tuber as the shoot grows. The shoots develop two glossy trifoliate leaves and a flower if the shoot is large enough. The foliage grows to 40 cm tall in good conditions.
The flowers can be either male or female on the same plant, and sex is determined by relative vigour and nutrition of the plant. The healthier the plant, the better the chances of it producing a female flower. This variation is more critical in some species than others, since some Arisaema species are more or less solitary tubers, and propagate better from seed.
A. ringens clumps up quickly, and is therefore one of the commonest species in cultivation.
As the tubers grow bigger and produce more buds, these mature into separate tubers as they go dormant in the autumn and as the old tuber rots out under the new one.
Arisaema ringens is a good compliment for hostas with its shiny trifoliate leaves and its preference for similar conditions, though it will not tolerate as much moisture as hostas.
Occasionally they set seed, but seldom become a weed problem as some of the other species can. Corms may be lifted and separated at any time in the dormant period which is from May to mid September.
Arisaema ringens is often considered too common to grow commercially, but some small perennial nurseries grow a few.
Parva Plants email: firstname.lastname@example.org occasionally list Arisaema species.
Yaku Nursery have it listed on their perennial list at: http://www.vanplant.co.nz/yaku/perennials/
NZGOL Bulb nursery list - these nurseries may list it.