Lathraea clandestina
purple toothwort
Western Europe (France, Belgium, Spain, Italy)
Overview
Lathraea clandestina is a perennial root parasite with no green leaves and no chlorophyll, drawing all its nutrients from the roots of host trees such as willow, poplar, and alder. For most of the year it exists as a branching white underground rhizome clothed in fleshy, colourless scale-leaves. In late winter and spring it pushes clusters of stalkless, two-lipped flowers 0.75-2 inches (2-5 cm) long directly through the soil surface, vivid purple to violet, opening close to the ground above the host roots. There are no stems or foliage above ground; only the flowers appear, often in dense patches beneath damp waterside trees. After flowering it sets capsules that expel seed explosively, and the plant returns underground until the next spring. Because it requires a living host, it cannot be grown in ordinary soil and must be established near suitable tree roots, usually by sowing fresh seed at the base of a willow or poplar. Once attached it can persist and spread for years, forming large flowering colonies. It causes little visible harm to vigorous host trees but draws steadily on their resources.
Native Range
Lathraea clandestina is native to western Europe, in Belgium, France, Spain, and Italy, where it parasitises waterside trees. It grows in damp woodland, riverbanks, and the moist ground beneath willows, poplars, and alders.Suggested Uses
Grown at the base of waterside willows, poplars, and alders in woodland and streamside gardens, where it carpets the ground with early purple bloom. Suits naturalistic damp plantings and shaded riverbanks. It is a curiosity for collectors of parasitic and woodland plants rather than a bedding subject.How to Identify
Appearance
Size & Dimensions
Height1" - 3"
Width/Spread1' - 4'
Reaches mature size in approximately 4 years
Bloom Information
Flowering occurs from late winter into spring, roughly February to May, when dense clumps of purple flowers break through the soil surface. The display lasts several weeks and is the only above-ground sign of the plant. Seed capsules then form at ground level and scatter seed before the plant withdraws underground.
Growing Conditions
Sun Requirements
Requires 2-6 hours of direct sunlight daily
• Full Sun: 6+ hours of direct sunlight
• Partial Shade: 3-6 hours of direct sunlight
• Full Shade: Less than 3 hours of direct sunlight