Ajuga reptans

Bugle is a perennial herb that can spread by seed or, more typically, by means of creeping stems known as 'stolons' or 'runners' (3). It flowers from late April to early July (6). The flowers are pollinated by bees, although self-fertilisation is also possible (2).  Bugle was, in the past, a well-known medicinal herb. It was used mainly to treat wounds, and was once widely planted in gardens to provide a ready supply (5).

Bugle is a common herb that often grows in large clumps (4). The flowers are deep purplish blue, rarely pink or white (2), and are arranged on tapering flower stalks. The dark leaves have an unusual colouration, with a purplish-brown or violet sheen on a dark green ground colour (4). An alternative name for this plant, 'thunder and lightning' is thought to refer to the contrast between the shiny highlights and deep background colour of the leaves (5). The common name 'bugle' does not refer to the musical instrument, but is thought to derive from 'bugula', s name used by apothecaries (5), which may in turn be a corruption of the generic Latin name 'Ajuga' (6).

This introduced perennial plant is 4-12" tall and unbranched, consisting of a rosette of leaves and a flowering stalk. The basal leaves are up to 3" long and 1" across. They are evergreen or semi-evergreen, obovate (spoon-shaped), and nearly hairless. Their margins are crenate and slightly undulate. The flowering stalk is 4-angled and slightly pubescent or hairy. The opposite leaves along this stalk are similar to the basal leaves, except that they are smaller in size and ovate. The flowers occur in a whorled spike along the upper half of the leafy stalk. They are produced in abundance and densely distributed along this spike. Each tubular flower is about 1/2–2/3" in length, consisting of a 2-lipped corolla and a green calyx with 5 teeth. The corolla is usually various shades of blue-violet, and less often pink or white. There are dark blue-violet lines that lead toward the throat of the corolla; they function as nectar guides. The upper lip of the corolla is truncated and very small, while the large lower lip has 3 rounded lobes. The middle lobe of the lower lip is notched at its tip and the largest in size. The outer surface of the corolla behind the lobes is conspicuously hairy; this causes the flower buds to appear hairy. The blooming period occurs during the spring and lasts about 2-3 weeks. Each flower is replaced by 4 nutlets that are oval-shaped and pitted across the surface. The root system consists of a crown of fibrous roots. Green stolons up to 12" long are produced from the rosette of basal leaves. They are largely naked, except for a few small leaves that are narrowly ovate. These stolons often form new plantlets by rooting at their tips. Carpet Bugle can reproduce by seeds or vegetatively by means of these stolons; it often forms colonies.

Different cultivars of Carpet Bugle are available through the horticultural industry that can vary considerably in the color of their flowers and foliage. The only other Ajuga sp. that has naturalized in Illinois is Ajuga genevensis (Geneva Bugle). This species is slightly taller with stems and leaves that are more hairy than Carpet Bugle; it also doesn't produce stolons. Carpet Bugle is easy to distinguish from other members of the Mint family because of the following combination of features

Perennial herb, 10-30 cm, with long leafy, rooting stolons. Stems simple, usually hairy on 2 opposite sides only. Leaves: basal in a rosette; lamina obovate to oblong-elliptic, entire to obscurely crenate; base attenuate into a broad petiole; apex obtuse; cauline few, ± sessile. Upper bracts tinged purple or blue, shorter than the flowers. Calyx campanulate. Corolla blue, less often pink or white.

reptans: creeping, referring to the stolons

Ajuga reptans L.:
Canada (North America)
United States (North America)
South Africa (Africa & Madagascar)
Venezuela (South America)

Note: This information is based on publications available through Tropicos and may not represent the entire distribution. Tropicos does not categorize distributions as native or non-native.

Throughout most of Europe; also SW Asia and N Africa

Canada

Origin: Exotic

Regularity: Regularly occurring

Currently: Unknown/Undetermined

Confidence: Confident

United States

Origin: Exotic

Regularity: Regularly occurring

Currently: Unknown/Undetermined

Confidence: Confident

This plant is widespread throughout Britain, up to altitudes of 760 meters (3). Elsewhere it is found throughout much of Europe, the Caucasus (Armenia, Georgia and Azerbaijan), south west Asia, Algeria and Tunisia (2).

Found in damp broadleaved woodlands, typically in shaded places, and in damp meadows and pastures (2).

The flowers are pollinated by bumblebees and other long-tongued bees. According to sources within the horticulture industry, the foliage is rarely bothered by rabbits and deer. Photographic Location

Foodplant / open feeder
gregarious larva of Athalia cordata grazes on leaf (underside) of Ajuga reptans

In Great Britain and/or Ireland:
Foodplant / parasite
Erysiphe biocellata parasitises live Ajuga reptans

Foodplant / feeds on
scattered pycnidium of Phyllosticta coelomycetous anamorph of Phyllosticta ajugae feeds on live leaf of Ajuga reptans
Remarks: season: autumn

Foodplant / spot causer
hypophyllous colony of Ramularia ajugae causes spots on live leaf of Ajuga reptans

Foodplant / sap sucker
nymph of Tingis reticulata sucks sap of Ajuga reptans

The following is a representative barcode sequence, the centroid of all available sequences for this species.

Barcode of Life Data Systems (BOLDS) Stats
Public Records: 14
Specimens with Barcodes: 16
Species With Barcodes: 1

Canada

Rounded National Status Rank: NNA - Not Applicable

United States

Rounded National Status Rank: NNA - Not Applicable

Rounded Global Status Rank: GNR - Not Yet Ranked

Common and widespread: not threatened (3).

This species is not threatened.

Conservation action is not required for this very common species.

The preference is partial sun, slightly moist to mesic conditions, and a fertile loamy soil that is somewhat acidic. If the soil is poorly drained and soggy, crown rot can develop and spread rapidly. In sandy soil, the roots are occasionally attacked by nematodes. Range & Habitat