Published online by Cambridge University Press: 18 November 2009
The stem eelworm Anguillulina dipsaci (Kühn) Gerv. & v. Ben., is responsible for disease in numerous plants, amongst which are teazle, Dipsacus fullonum L., the type host and red clover, Trifolium pratense L. In both cases seed harvested from infected plants will often be infected by the stem eelworm in spite of the greatest care in dressing the seed.
Kühn (1857) in describing the parasite for the first time said:— The seeds of the diseased teazles differ from those of the healthy ones. They are not half so large nor so sharply angular. Whilst the pappus of the healthy seed is stalked that of the diseased seed is sessile and almost twice as large. The worms do not completely fill the diseased seed but occur within the atrophied ovule and also as small clumps of worms within the tissue of the abnormally thickened seed coat. The worms are found not only within the diseased seeds but in all other parts of the head including the pith where they cause not only abnormal growth but death and brown discolouration of the tissues.