Delphinium

Delphinium
Delphinium staphisagria
Scientific classification
Kingdom:	Plantae
(unranked):	Angiosperms
(unranked):	Eudicots
Order:	Ranunculales
Family:	Ranunculaceae
Genus:	Delphinium L.
Species
See text

Delphinium is a genus of about 300 species of perennial flowering plants in the family Ranunculaceae, native throughout the Northern Hemisphere and also on the high mountains of tropical Africa.^[1]

The common name "larkspur" is shared between perennial Delphinium species and annual species of the genus Consolida.^[2] Molecular data shows that Consolida, as well as another segregate genus, Aconitella, are both embedded in Delphinium.^[3] The name "delphinium" derives from the Latin for "dolphin", referring to the shape of the nectary.

Description

Flower of most species have 5 spreading sepals and 4 petals (e.g. Delphinium nuttallianum).

In high mountain habitat, central Utah rangelands.

The leaves are deeply lobed with 3 to 7 toothed, pointed lobes in a palmate shape. The main flowering stem is erect, and varies greatly in size between the species, from 10 centimetres in some alpine species, up to 2 metres tall in the larger meadowland species.

In June and July (Northern Hemisphere) the plant is topped with a raceme of many flowers, varying in color from purple and blue, to red, yellow, or white. In most species each flower consists of five petal-like sepals which grow together to form a hollow pocket with a spur at the end, which gives the plant its name, usually more or less dark blue. Within the sepals are four true petals, small, inconspicuous, and commonly colored similarly to the sepals. The eponymous long spur of the upper sepal encloses the nectar-containing spurs of the two upper petals.^[4]

The seeds are small and often shiny black. The plants flower from late spring to late summer, and are pollinated by butterflies and bumble bees. Despite the toxicity, delphinium species are used as food plants by the larvae of some Lepidoptera species, including the dot moth and small angle shades.^{[citation needed]}

Toxicity

All parts of these plants are considered toxic to humans, causing severe digestive discomfort if ingested, and also skin irritation.^[2][4][5]

Larkspur, especially tall larkspur, is a significant cause of cattle poisoning on rangelands in the western United States.^[6] Larkspur is more common in high-elevation areas, and many ranchers will delay moving cattle onto such ranges until late summer when the toxicity of the plants is reduced.^[7] Death is through cardiotoxic and neuromuscular blocking effects, and can occur within a few hours of ingestion.^[8]

Species

Species include:^[9]

Delphinium elatum,
Candle larkspur

Delphinium cardinale, Scarlet larkspur.

Ecology

Delphiniums can attract butterflies and other pollinators.^[10]

Cultivation

Various delphinium species are cultivated as ornamental plants, for traditional and native plant gardens. The numerous hybrids and cultivars are primarily used as garden plants, providing height at the back of the summer border, in association with roses, lilies and geraniums.

Most delphinium hybrids and cultivars are derived from Delphinium elatum. Hybridisation was developed in the 19th-century, lead by Victor Lemoine in France.^[11] Other hybrid crosses have included D. bruninianum, D. cardinale, D. cheilanthum and D. formosum.^[12]

Numerous cultivars have been selected as garden plants, and for cut flowers and floristry. They are available in shades of white, pink, purple, and blue. The blooming plant is also used in displays and specialist competitions at flower and garden shows, such as the Chelsea Flower Show.^[13]

The 'Pacific Giant' hybrids are a group with individual single-color cultivar names, developed by Reinelt in the United States. They typically grow to 4–6 feet (1.2–1.8 m) tall on long stems, by 2–3 feet (0.61–0.91 m) wide. They reportedly can tolerate deer.^[10] Millennium delphinium hybrids, bred by Dowdeswell's in New Zealand, are reportedly better in warmer climates than the Pacific hybrids.^[14][15] Flower colors in shades of red, orange, and pink have been hybridized from Delphinium cardinale by Americans Reinelt and Samuelson.^[12]

The following delphinium cultivars have received the Award of Garden Merit from the British Royal Horticultural Society:

Other uses

Delphiniums displayed at the Chelsea Flower Show.

The juice of the flowers, particularly Delphinium consolida, mixed with alum, gives a blue ink.^[44]

Medicinal

All parts of the plant contain various diterpenoid alkaloids, typified by methyllycaconitine, so are very poisonous.^[5] In small amounts, extracts of the plant have been used in herbal medicine.

Delphinium is used to treat intestinal worms, fluid retention, poor appetite, and trouble sleeping (insomnia). It is also used as a sedative to cause relaxation.^[45] Gerard's Herbal reported that drinking the seed of larkspur was thought to help against the stings of scorpions, and that other venomous animals could not move when covered by the herb, but that he did not believe this himself. Mrs. Grieve reports that the seeds can be used against parasites, especially lice and their nits in the hair. A tincture is used against asthma and dropsy.^[46]

The plant was connected to Saint Odile of Alsace, a patroness of good eyesight, and so in popular medicine was used against eye diseases.

External links

Wikimedia Commons has media related to Delphinium.

• GRIN: Species in the genus Delphinium' — with links by species for information + synonyms.
• USDA-ARS: Larkspur—Delphinium spp. Fact Sheet — native U.S. species and grazing toxicity.
• MBG—Kemper Center for Home Gardening: Delphinium "Pacific Giant Hybrids" — horticultural information.
• Dowdeswell's Ltd: "Growing New Millennium Delphiniums in the U.S. & Canada" — horticultural information.

A Delphinium cultivar.

References