- Written also: Northern Wolf’s-bane
- Latin synonym: Aconitum septentrionale
- Family: Buttercup Family – Ranunculaceae
- Growing form: Perennial herb. Rootstock tuberous.
- Height: 1–2 m (40–80 in.). Stem hollow, upper part densely sticky-haired.
- Flower: Perianth irregular (zygomorphic), blue–purple (occasionally light red or yellow), up to 5 cm (2 in.) high, with greyish hairs. Sepals 5, petaloid, uppermost hooded, over 3 times as high as broad. Petals 2, nectariferous, inside hood-like sepal. Stamens many. Gynoecium separate, pistils 2–5. Inflorescence a long, quite dense unbranched–branched raceme.
- Leaves: Alternate, basal leaves long-stalked, stem leaves short-stalked–stalkless. Blade with palmate venation, hairy, 3–5-lobed, lobes with large, sharp teeth, and further lobed.
- Fruit: Arching, glabrous, terminated by a short bristle, 11–17 mm (0.44–0.68 in.) long follicle, usually 3 together.
- Habitat: Broad-leaved forests, beside coppices and rich mixed swamps. Sometimes ornamental and an escape from cultivation.
- Flowering time: June–July.
- Endangerment: Vulnerable, protected in all of Finland.
Northern wolfsbane rarely flowers in Finland, but when it does it’s quite a sight. It grows wild in only seven places in North Karelia on ridges, stream banks and forest margins around Kitee and Tohmajärvi. Its Finnish habitats, which are very rich, constitute the western border of its habitat, which stretches far to the east. These peculiar large meadows are regarded as being worthy of their own specified plant biotype, called Aconitum type (AT) groves. On the fell areas of Sweden and Norway northern wolfsbane is quite common.
Northern wolfsbane grows quickly in the spring using the nutrition stored in its thick, tuberous rootstock, and its leaves are already fully formed when other plants are just beginning to put theirs out. The plant grows year after year for up to a decade, each year with slightly bigger leaves, until eventually it is large enough to flower. The flowering stem can reach a height of 2 metres (80 in.) and the flowers are impressive. It is no wonder that in ancient mythology the old Finnish Pagan god Ukko Ylijumala took the plant’s highest, helmet-like petal for his cap. As can be deduced from the flower’s special structure, its pollination biology is highly specialised. Northern wolfsbane is pollinated by _ Bombus consobrinus_, the only bee in northern Europe that has clearly specialised in a single plant to provide its nutrition. The only other species that can pollinate the plant is the bumblebee.
Members of genus Aconitum are among Finland’s most poisonous plants: even a small dose is fatal and long-term skin contact can be enough to cause poisoning. In Finland two other members of the genus grow as escapes or leftovers from cultivation: monkshood (A. napellus) and variegated monkshood (A. x stoerkianum). Their flowers have clearly lower hoods, and monkshood’s is wider than high and variegated monkshood’s is about as wide as it is high. Additionally, their leaves are more lobed than northern wolfsbane’s. When not flowering, northern wolfsbane can be mixed also with candle larkspur (Delphinum elatum).