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Into the light, the flowering of Toothwort (Lathraea squamaria)

11 May 2012

A population of Toothwort has been discovered growing amongst shrubs at the Botanic Garden.

Staff at the University of Bristol Botanic Garden have discovered a population of Toothwort Lathraea squamaria growing amongst shrubs at the Garden.

Lathraea squamaria

The translucent white flowers of Lathraea squamaria

Toothwort, a member of the broomrape family Orobanchaceae is parasitic and has no green leaves or stems relying totally on its host for its food source. The plants were found growing on the roots of sycamore and Aucuba japonica. Toothwort and the closely related Purple Toothwort, Lathraea clandestina, are both native to the United Kingdom and is normally found growing on hazel and willow and so it was a surprise to find it growing on these hosts.

The growth goes on below the soil surface away from light and unnoticed by passers by. Only when it is has gained enough energy reserves does it produce flower spikes which appear in Spring. Each spike is translucent white, sometimes tinged pink with numerous small flowers that arch towards the ground. The clump which numbers eighty four flower spikes has already been pollinated and seed is being set. A careful watch is being kept on the plant as some spikes appear to have been eaten by rodents. It is hoped that by sowing the seed on other potential hosts more clumps of this plant can be established at the Botanic Garden and elsewhere within the University estate.