. The fungi which cause plant disease . Plant diseases; Fungi. 274 THE FUNGI WHICH CAUSE PLANT DISEASE Fig. 203.—G. tubifor- mis, peiithecia. After Winter. apically thickened and opening by a pore; spore elliptic, 1-celled, hyaline; paraphyses none. This genus of some twenty-five species contains G. tubiformis (Tode) Sacc. which is said to be the ascigerous stage of Lepto- thyrium alneum Sacc. growing on Alder. Two other species, G. fimbriata and G. coiyli are found on hornbeam and hazel respectively. Gnomonia Cesati & de Notaris (p. 264) Perithecia covered, or eriunpent, submembranous, gl
. The fungi which cause plant disease . Plant diseases; Fungi. 274 THE FUNGI WHICH CAUSE PLANT DISEASE Fig. 203.—G. tubifor- mis, peiithecia. After Winter. apically thickened and opening by a pore; spore elliptic, 1-celled, hyaline; paraphyses none. This genus of some twenty-five species contains G. tubiformis (Tode) Sacc. which is said to be the ascigerous stage of Lepto- thyrium alneum Sacc. growing on Alder. Two other species, G. fimbriata and G. coiyli are found on hornbeam and hazel respectively. Gnomonia Cesati & de Notaris (p. 264) Perithecia covered, or eriunpent, submembranous, glabrous, ostiole more or less elongate; asci elUpsoid or fusoid, apically thick- ened, opening by a pore; spores elongate, hyaline, 2 to 4-celled; paraphyses none. There are some sixty species. Fusicoccum, Myxosporium, Sporo- nema, Glceosporium, Marssonia, Asteroma, Leptothyrium occur in some species as the conidial form. The ascigerous form usually follows as a saprophyte after the parasitic conidial stage. G. veneta (Sacc. & Speg.) Kleb.^^'- ^^^- ^^^' »35 Perithecia immersed, subglobose or sUghtly flattened, 150- 200 n, short, rostrate; asci long-clavate, 48-60 x 12-15 n, gen- erally bent at right angles at the base, apically very thick, opening by a pore; spores 14-19 x 4-5, straight or slightly curved, unequally 2-celled, the upper cell longer. Conidia variable in habitat, and habit. (1) (= Glceosporium nervise- quum) acervuli subcuticular 100- 300 n; conidiophores short, conidia oozing out in a creamy-white mass, hyaline, ellipsoid, 10-14 x 4^6 ju, pointed at one end and rounded at the other. (2) (=G. platani) acervuli sub- epidermal, conidiophores long; conidia as above. (3) (=Discula platani=Myxosporium valsoideum) form- ing minute, subepidermal, erumpent pustules on twigs; conidia elliptic to oblong, hyaline, 8-14 x 4-6 m; (4) ( =Sporonema platani. Fig. 204.—G. veneta, perithe- cium. After Please note that these images are extracted from scanned page
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectfungi, bookyear1913
