330 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 



concealed beneath the cuticle, but there is no true perithecium or recep- 

 tacle, and the conidia are formed upon a kind of cushion, or stroma, 

 supported at first on rather long branched stalks. They are elliptical or 

 oblong, either straight or slightly curved, often with two nuclei, but 

 \ a l iable in size (5-9 x 3-4 /x), pale olive, oozing out, when mature, either 

 in black tendrils or irregular inky masses. 



This species was made known in 1845, but has not been much heard 

 of since. It is allied to the species of Anthracnose, but with coloured 

 conidia. 



Another fungus, bearing the sporidia contained in asci (Nectria 

 pandani), has also been found on Screw Pine, of which it has been sug- 

 gested that the above is a condition, but we think that the suggestion is 

 ( f very little value, as there is no precedent for such an association. 



Ann. Sci. Nat. Bot. 1845, p. 66; Mass, PI. Dis. pp. 293, 431 ; Sacc. 

 Syll iii. 3985. 



Palm-leaf Pustule. 

 Graphiola phcewicis (Poit.), PI. XV. fig. 32. 



This peculiar kind of fungus is found on the living or fading fronds 

 of Palms in conservatories, in Britain and most other parts of Europe, in 

 North America, parts of South America, Ceylon, India, and Algeria. 



The pustules appear like hard, black, superficial, round excrescences 

 upon the leaves, being developed beneath the cuticle, but soon erumpent 

 (1-H mm. diam.). They possess an outer horny coat, and a thinner 

 inner coating, which is filled with fertile threads, and numerous rather 

 small (3-6 /u) globose yellowish uredospores, with a hyaline membrane. 

 When the spores are dispersed the threads remain for some time in a tuft 

 within the remains of the black outer coat, looking scarcely like either a 

 rust or a smut. 



Sacc. Syll vii. 1915 ; Cooke, Hdbk. No. 1637 ; Tubeuf, Dis. p. 326 ; 

 Cooke, Hdbk. Austr. Fungi, t. 28, f. 260. 



The black mould Zygosporium oscheoides (fig. 23) has also been found 

 on Screw Pine and the foliage of palms in tropical countries. 



Palm-leaf Black Mould. 



lletcrosporium minutulum (C. k M.), PI. XV. fig. 33. 



This mould is of the same nature as one which is very destructive to 

 Carnations, and occurs on the leaves of Palms, in this instance on 

 ( ImHLGerops humilis. It forms dark olive velvety patches of variable size 

 and form, sometimes considerable in extent, with a creeping mycelium. 

 The threads are mostly collected in tufts, and are rather short, flexuous, 

 and sparingly septate, of a pale olive colour. Conidia with one or two 

 ■ pta, elliptical, rounded ;it the ends, but not constricted at the joints, 

 pale olive (16-20 x (i H/x), and externally rough, as in other species of the 

 L'cmis. 



Thifi i also ;<t present only recorded for Britain, but it belongs to such 

 a persistent group of parasites that it will probably be heard of again. 

 Qtevillea, xvi 11 ; Sacc. Syll. x. 7767. 



