Mclaiiopsicliiui}).. 163 



MELANOPSICHIUM Beck. 



Mycelium intermixed with tlie diseased plant tissues, which arc hollowed 

 out into cavities, containing the spore-bearing gelatinous hyphae. 



Sori on various parts of the host, forming compact, hard, conspicuous, 

 gall-like masses, black when cut across, and the galls consisting of a mixture 

 of plant tissue and hyphae. 



Spores single, as inUstilago, and germination similar, developed in cavities 

 of various shapes and sizes, which are sometimes confluent. 



There is only a single species of this genus known, which was formerly 

 placed under Ustilago. It was originally found in South America and now 

 in the United States and Australia. The development of the spores in cavities, 

 the walls of which consist of the plant tissues and the mycelium intermixed, 

 is the characteristic feature of the genus. 



Australian species, 1. 



'Pohjqonum. 

 19, Melanopsichium austro-americanum (Speg.) Beck. 



Beck, Ann. K. K. Natur. Hofmus. Wien. p. 22 (1894). 

 Sacc. Syll. VII., p. 457 (1888). 



Ustilaqo austro-americana Speg. Fung. Argent., pug. 4, No. 45 

 (1881) 

 Forming compact, hard, rough, lobed, oblong, ruddy-brown galls around 



joints of stem, up to 1 cm. in size, black when cut across. 

 The gall consists of the various tissues of the stem — epidermis, cortex, 

 and fibro-vascular bundles — for the most part hollowed out into 

 cavities which are the sori. 

 Sori of various shapes and sizes, generally marked off by definite tissue, 

 round to oval or oblong, adjoining one another and sometimes con- 

 fluent ; ranging from 70 /i long w^hen young up to 500 /< or more 

 when mature. 



Spores olivaceous, ellipsoid to ovate, prominently echinulate, 

 10-14 X 7-8 II. 

 On Polygonum sp. 



Queensland — Near Brisbane, April, 1879 (Bancroft). 

 The spores are developed in gelatinous hyphae which deliquesce and set 

 free the spores in the cavity. As the sori are completely surrounded by the 

 outer tissues of the stem, the spores can only escape by the decay of the tissue, 

 or by the absorption of water and the oozing out of the ripe spores. Only 

 a single species of this genus has, so far, been known, and although in the 

 United States specimens the sori were chiefly in the inflorescence, and in 

 South America, where it was first found, chiefly on the leaves, yet the general 

 characters of this specimen agree so well with the type, that I have no hesita- 

 tion in referring it to the same species. A specimen examined from Clinton's 

 Ustilaginese C. 35, on Polygonum lapatJiifolium had the same characters. 



This Queensland specimen was given by Cooke in his Handbook of 

 Australian Fungi as Ustilago emodensis Berk. 



Berkeley founded this species on a single specimen from Tonglo, in the 

 Sikkim Himalaya, 10,000 feet high, and he described it as forming a lobed 

 tubercle ; spores ovate or elliptic, deep lilac, smooth, very minute, traversed 



G 2 



