. Diseases of cultivated plants and trees. Plant diseases; Plants -- Wounds and injuries; Plants, Protection of; Trees -- Diseases and pests. 220 DISEASES OF CULTIVATED PLANTS Differs from Sphaerella in the spores being more than i-sep- tate, and from Leptosphaerella in the absence of paraphyses. The majority of species occur on fallen leaves and are considered as saprophytes, but nothing certain is known of the life-history of most forms. Yew leaf scorcli (^Sphacnilina taxi, Massce) is at times the cause of serious damage to yews. The leaves are attacked, the first indication of mischief bein
. Diseases of cultivated plants and trees. Plant diseases; Plants -- Wounds and injuries; Plants, Protection of; Trees -- Diseases and pests. 220 DISEASES OF CULTIVATED PLANTS Differs from Sphaerella in the spores being more than i-sep- tate, and from Leptosphaerella in the absence of paraphyses. The majority of species occur on fallen leaves and are considered as saprophytes, but nothing certain is known of the life-history of most forms. Yew leaf scorcli (^Sphacnilina taxi, Massce) is at times the cause of serious damage to yews. The leaves are attacked, the first indication of mischief being a change from the normal dark green to a brown colour. At a later stage the upper surface of the leaf is densely studded with minute pustules or warts, corresponding to the embedded perithecia, the mouth alone protruding through the ruptured epidermis. As a rule when this parasite once attacks a tree it spreads very rapidly, so that within a short period of time all the leaves have fallen; many of the younger shoots are also killed and fall to the FlC. 63. — I, Sphacrulina taxi, on yew lc;if, slightly mag. ; 2, section of pcrithecium. slightly mag. ; 3, ascus containing spores, highly mag. ; 4, free ascospores, highly mag. If the disease attacks a tree for two or three years in succession it is usually killed outright. Fortunately this is not a common disease, or at all events it is not very frequently recorded. I have seen it at work in Cornwall, and also in Yorkshire, where a number of fine yew-trees growing in a churchyard were being killed. Mr. F. Moore of Glasnevin informed me that he had noticed the disease in three counties in Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Massee, George, 1850-1917. New York : Macmillan
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Keywords: ., bookpublishernewyorkmacmillan, booksubjectplantdis, bookyear1910
