Perennating Derivation of the botanical name: Ajuga, from the Greek a "not, without", and Latin iugum, i iungo "a yoke," Greek zygon, zygos, "yoke"; an allusion to the fact that the calyx is not divided and is in fact a single petal. According to Umberto Quattrocchi, it also could be a variant of the old Latin name abiga, ae abigo "to drive away" applied by Plinius to a plant which has the power of producing abortion to Chamaepitys, ground-pine, a species of Teucrium. The standard author abbreviation L. The standard author abbreviation Schreb.
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WCA Schedule 8. Status in Europe: Not threatened. It is an attractive plant with intense yellow flowers and a strong resinous scent when crushed or trampled. Characteristic habitats include the upper edges of cultivated fields, crumbling banks and track sides, ground disturbed by scrub removal, road works or pipe-laying operations, and the edge of chalk or gravel pits.
Dry sun-baked slopes are favoured, particularly on chalk escarpments. It is a poor competitor, confined to bare ground and the earliest seral stages. It used to be a characteristic member of the flora of temporary arable or fallow fields on the chalk downs of Surrey and Kent.
Though it is no longer a typical arable weed, it sometimes still occurs with Filago pyramidata, T. It may grow on bare chalk or chalky clay, but more typically prefers a thin surface layer of sandy or gravelly drift. Commoner associates include Arenaria serpyllifolia ssp. The flowering period is unusually long, extending from June to October, depending on whether the seedlings are autumn-, winter- or spring-germinated.
Autumn-germinated plants survive the winter as rosettes. Although frequently thought of as an annual, some robust plants are plainly short-lived perennials with a woody tap-root. There is also evidence that seeds fail to ripen in cold summers Grubb It may owe its survival here at the northern edge of its range to the flexible seed germination strategy, which may be genetically controlled.
This helps to explain its erratic appearances, flowering prolifically after sudden disturbance, and then disappearing again as the vegetation closes.
On nature reserves it can be induced to flower annually by shallow ploughing or rotavating. This species has become much less frequent during the past 50 years, partly because of the use of herbicides, but more because of the abandonment of fallow land on chalk slopes, and the spread of coarse grass, scrub and secondary woodland on its downland localities. It is particularly vulnerable at the outlying parts of its British range in Hampshire and the Chilterns where only a few sites remain; less so on the North Downs in Surrey and Kent where new sites are still being found.
Most of the known populations are small, however, and the species now often depends on conservation management to survive. Exceptionally, a population may number more than 1, plants. The improved level of scrub control and the restocking of some old sites with sheep are hopeful signs, as is the possible prospect of hotter, drier summers. Outside Britain, A. Its distribution extends eastwards into the Levant and southwards to North Africa.
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