246 FUNGOID PESTS OF CULTIVATED PLANTS. 



All diseased leaves should be collected and burnt, otherwise the disease 

 may return the following year. It is recommended that the crop be lifted 

 when the disease appears on the leaves, and before it reaches the root. 

 Diseased roots must not be stored. 



Prill. Mai. Pl.Agri. ii. p. 263 (1897) ; McWeeney, Journ. Roy. Agri. 

 Soc. vol. vi. pt. 3, 1895, with figs. ; Mass. PI. Dis. p. 110. 



BOOT TUBERCLES. 



The root tubercles of the Leguminosce have been the source of con- 

 siderable speculation for many years, but the general impression now is 

 that they are not at all of fungoid origin. 



CLOVER-LEAF CUPS. 

 Pseudopeziza Trifolii (Lib.), PI. XXIV. fig. 37. 



This little parasite is not uncommon on fading leaves of different 

 species of Clover, chiefly upon the upper surface. Although, in its form, 

 it is a little fleshy cup- shaped Peziza, it differs in being produced beneath 

 the cuticle, and bursting through by rupture of the cuticle, which then 

 encircles it with its rough torn margin cups about ^ mm. broad, a little 

 concave, smooth, and honey-coloured. The disc composed of compacted 

 cylindrical asci, pressed side by side, and each enclosing eight elliptical 

 sporidia (10-15 x 5-7/x), containing two nuclei. 



It has been reported from France, Belgium, Germany, Portugal, Italy, 

 and North America. In Britain it is very widely distributed. 



Sacc. Syll. viii. 2970 ; Phil. Disc. p. 199 ; Cooke, Hdbk. No. 2270 ; 

 Mass. PL Dis. p. 144, fig. 29. 



A similar species (Pseudopeziza Medicaginis) occurs on the living 

 leaves of Lucerne, but it is uncertain whether it has occurred in Britain. 



CLOVER SCLEROTE. 

 Sclerotinia Trifoliorum (Erik.), PI. XXIV. fig. 38. 



In some seasons Clover is subject to attacks from this parasite, as are 

 also Sainfoin, Lucerne, and others of the family. The leaves are at first 

 frosted with a delicate white mycelium, and finally shrivel and decay. In 

 the winter minute black sclerotia are formed on the dead leaves and roots. 

 With the spring and summer these sclerotia germinate and produce one or 

 two small Pezizce, or cup-shaped fungi, of the Sclerotinia type, with a long 

 and slender stem, bearing at the apex a small fleshy brown cup, the inner 

 or concave surface composed of a compact layer of cylindrical cells or asci, 

 placed side by side, and each of them enclosing eight colourless elliptical 

 sporidia (16-18 x 6-8f/). When these sporidia germinate in their turn, they 

 are competent to inoculate other Clover plants, and perpetuate the disease. 



When this disease appears in a field it would be advisable to relinquish 

 a Clover crop for several years. 



Recorded in Germany and Scandinavia. 



-Sacc. Syll. viii. 800 ; Mass. PL Dis. p. 155 ; Phil. Disc. p. 118 ; Prill. 

 Mai. PL Agri. ii. p. 413, with figs. ; Gard. Chron. Mar. 17, 1906, p. 176. 



