THE "KEW BITLLETIN." 40 THERE is always an interest in turning
over the pages of the Sew Bulletin to look for the new discoveries of the year. The list of new plants in any year is generally a pretty long one, and the new introductions of the year 1910 occupy some thirty-four columns. But as interesting as any of the garden flowers is the new lawn grass known as blue couch, which seems to have first come into prominence in Australia in 1910, and to be a discovery of considerable importance for gardeners in warm countries. Hitherto the chief grass used in Australia for lawns has been the ordinary couch—not the mischievous Triticum repene of England, but a separate variety, Cynodon dactylon. The new blue couch seems to he a stronger grass which eradicates all other weeds and grasses on a lawn and recovers so quickly after a. drought that, though apparently the lawn is dead, three days after wetting it needs the mowing machine. One wonders how it would suit a site on hot sand in England. Another new addition to the English garden is less welcome. An epidemic has broken out among lilac trees, caused by a fungus known as Helmintho sporium syringae. The leaves are attacked by a brown stain which runs down each half of the leaf at some distance from the midrib : this stain spreads but does not seem to touch the edge of the leaf. The spores multiply at a great pace and are washed by rain or carried by birds to other leaves, disfiguring the whole bush. The remedy is spraying with a solution of potassium sulphide and burning the diseased leaves. But the lilac epidemic is not so disastrous as a now disease which belongs peculiarly to the greenhouse. This is a paint-eating fungus, Phoma pig- mentivora, which has succeeded in establishing itself in newly painted hothouses : it flourishes in a high temperature and in damp. About a month after the house has been painted small rose-coloured specks appear on the paint, spreading to dark spots like sprinkled blood. The paint is ruined, and an instance is given of a firm which actually lost £200 by the destruction of work freshly done. The remedy fortunately appears to be simple : if two per cent. of carbolic acid is mixed with the paint the fungus cannot develop.
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