doubtful knight's-spur (Delphinium ajacis) — identification, habitat & look-alikes

Rocket larkspur is an garden plant introduced across much of the United States. Its threadlike leaves help distinguish it from many native larkspurs; the flowers can be blue, violet, pink, or white. Rocket larkspur is poisonous if eaten, including its seeds.

Appearance

Appearance: This annual grows about 12–28 in (30–71 cm) tall, with leaves cut into very narrow segments.
Flowers: A loose upright cluster carries blue, violet, pink, or white flowers, each with a narrow pointing back.
Flowering time: In North Carolina, it usually flowers from late May to early July.
Fruit: Each flower makes one seed pod, rather than a cluster of several pods.

Look-alikes

Dwarf larkspurDelphinium tricorne

In North Carolina, rocket larkspur has finely divided, threadlike leaves and flowers later in the season. Dwarf larkspur has broader leaf sections and usually blooms in spring.

Why they get mixed upBoth have blue to violet flowers with a backward-pointing spur.

Bee delphiniumDelphinium elatum

Bee delphinium is a perennial with broader leaf sections and usually much taller, denser flower spikes. Rocket larkspur is an annual with threadlike leaf pieces and a looser spike.

Why they get mixed upBoth are grown as tall blue garden flowers.

Three larkspurs you may see in North Carolina

	Life cycle	Leaves	Flowers
Doubtful knight's-spur	Annual	Threadlike leaf pieces	Loose spikes; late May to early July
Dwarf larkspur	Perennial	Broader leaf pieces	Spring flowers
Bee delphinium	Perennial	Broad leaf sections	Tall, dense spikes

Where it lives

Typical habitats: Gardens
Roadsides
Disturbed fields
Range: Native to parts of Eurasia and introduced across much of the United States. In North Carolina, it occurs in fields, along roads, and around fences.
Flowering: Flowers May–Jul
Flowers May–Jul

Cautions

Cautions: Rocket larkspur is poisonous if eaten; the seeds also contain toxic compounds.

Name and classification

About the name: It has also been called Consolida ajacis. It is also called doubtful knight's-spur.
Varieties and forms: Garden selections include short or tall plants and single or double flowers.

Conservation

IUCN Red List: NENot EvaluatedNot yet assessed

Culture and stories

Culture and stories: Its airy flower stalks are grown for cut flowers.

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