- Name also: Royal Knight’s-spur
- Latin synonym: Consolida regalis
- Family: Buttercup Family – Ranunculaceae
- Growing form: Annual herb.
- Height: 20–50 cm (8–20 in.). Stem branched from inflorescence, lower part glabrous, upper part hairy.
- Flower: Perianth irregular (zygomorphic), violet, sometimes dark blue or violet-red, often slightly flecked, 18–35 mm (0.72–1.4 in.) across. Sepals 5, petaloid, uppermost spurred, spur 15–25 mm (0.6–1 in.) long. Petals 1, blade 3-lobed. Stamens 5. Single carpel. Inflorescence quite broad, sparsely branched, quite lax raceme.
- Leaves: Alternate, lowest long-stalked, upper almost stalkless. Blade 2 times 3-lobed, lobes narrowly linear.
- Fruit: Usually glabrous, sometimes sparsely hairy, 8–15 mm (0.32–0.6 in.) long solitary follicle.
- Habitat: Fields, fallow land, banks, mills, harbours, railways, rubbish tips.
- Flowering time: June–August.
- Endangerment: Endangered.
Forking larkspur is native to the Mediterranean countries and the Middle East. Only a couple of species have managed to extend their area of distribution to Finland, and that has only been possible with human help. Forking larkspur used to be a common weed in fields in the Åland Islands and southwest Finland, but it was rare and casual elsewhere. Like many other field weeds the species apparently overwintered as seed in grain silos. Nowadays more efficient ways of cleaning the seed have seen a decline in forking larkspur and today it can be found around mills, harbours, railways and other changeable areas with lots of traffic. Farmers have not shed many tears for the species because the little black seeds that used to get mixed up with the flour contain poisonous alkaloids, as does the whole stem. Poisoning is similar to wolfsbane poisoning, but it is luckily less severe. The poison can of course be used in beneficial ways too: flower seeds have been used to drive out cancer and expel internal worms. To the naturalist’s eye the sight of a casual forking larkspur plant is beautiful, poison or not.
Doubtful Knight’s-spur & Oriental Knight’s-spur
Delphinium ajacis (Consolida ajacis) & Delphinium hispanicum (Consolida orientalis)
Doubtful knight’s-spur (also known as rocket larkspur) and Oriental knight’s-spur (also known as eastern larkspur) are popular garden summer flowers which sometimes manage to escape short distances.