REPORT OF THE BOTANIST. 87 



special peculiarity of certain individuals, for among a lot of diseased 

 plants a few may be found in perfect health ; while others again attribute 

 it to some alteration in or wounds of the roots. There is nothing known 

 of tlie true cause, however, beyond these and other like unattested 

 theories} neither is there any known remedy for the disease. 



THE SMUT OF TlKOTB.Y*—{Tilletia striaformis, Westd.) 



In May and June my attention was called to the prevalence of dis- 

 eased leaves on the timothy about Madison, Wis. The affected plants 

 were at this time somewhat smaller than those that were not diseased, 

 usually 4 to 5 inches high, with only three or four developed leaves : other- 

 wise they presented no unusual appearance when carelessly handled. 

 On a careful examination, however, one or more of the leaves were found 

 to be marked by lead-colored, slightly thickened lines, about one-sixty- 

 fourth inch wide and one-sixteenth to one-fourth inch long, running 

 lengthwise of the leaf. 



Sometimes but a single line or a series of lines was to be found on a 

 leaf, but usually there were several, in many instances the space be- 

 tween the two veins of the leaf being occupied by those discolorations, 

 which extended from the base nearly to the apex (Fig. 1). When one 

 of these leaves was cut or torn across, it was found that each of the 

 lead-colored lines referred to corresponded to a black, dusty mass, oc- 

 cupying the center of the leaf, and merely covered by the epidermis at 

 the top and bottom. Shortly afterwards the epidermis ruptured along 

 the dark lines, one side usually tearing before the other, and so exposed 

 the sooty substance, which was shaken from the cavities and dispersed 

 by the wind, under the action of which the leaves were soon reduced to 

 brown shreds, by which the diseased plants could bo readily distin- 

 guished, even from a distance (Fig. 2). • 



Under the microscope the dark mass fdling the leaf cavities was found 

 to consist of numberless irregularly round or ovoid, pale-brown spores, 

 usually measuring 10 to 12 ,«. in diameter, their surface closely beset 

 with short spines (Fig. 3). 



In its appearance to the naked eye, and in its microscopic characters, 

 this smut agrees closely with Tilletia de Varyana^ F. de 'Waldh. distrib- 

 uted on Rolcus mollis, fvom near Berlin, in Kabenhorst's Fungi Europici, 

 No. 3393. It is also indistinguishable from the English sjiecimens of 

 Ustilago salvcii, B. & Br., on an unnamed grass, in Cooke's Fungi Britt. 

 Exsicc, No. 57. These species are lield to be identical by Scliroiter and 

 ^Villter,f \v!io replace these, together with other other synon.vms, hy Til- 

 letia stria/drmi.s (Westendrop). 



The si)ecies occurs in Emope, in tin? Iquvi.'^ of Agrofttis sfoloiii/cm, 

 A. vvlr/ari.s, Calaiiiafjroati.'i Jtallcriana, Milluni effusum, Jfolcvs hniahis. 

 II. mollis, A)-rhcnni}ierii m arenacciim, Briza media, Poa j;>vi/cn.s'v.s, D(tcli/li.s 

 ijliymcyata, Fcstuca ovina, F. clatior,Bromus incrmis, and Lolinm po anne. 

 1 have collected it in Wisconsin, in the spring, on timothy {riileuni pra- 

 tciisc) and on the glaucus wild ry a {Elymus Canadeuffis, var. glauci/oliiis); 



* This cbaptcr, cm a disease of the most iinportaut meadow-nrrass of the NorMicni 

 States, has liecn prepared at the request of the assistant botanist of the Departmont, 

 by Prof. William Tteh;ase. 



ISchra^tcr : Cohn's Beitrilge, ziir Biol, dcr Pflaiizen,2, pp. 3C6, VS7. , 



Winter: PLlzo, in RabealiorHt'H Isa-yplo^^aiuea-Flora, 1, p. 108. 



