SCHIZOTHYRIUM. 



Schizothyrium, Desmaz ; Ann. Sci. Xat., Ser. iii. vol. xi. 

 (1849), p. 360; Eehm, in Krypt.-Flor., Hyst., p. 75; Sacc, 

 Syll., ii. p. 723 (defined by mistake as having the spor> - 

 continuous). 



The present genus holds an intermediate position between 

 the Hysteriaceae and the Phacidiaceae, leaning towards the 

 former in general habit, and towards the latter in the some- 

 what fleshy ascophore, which is not so carbonaceous and 

 rigid as in typical members of the Hysteriaceae. 



Schizothyrium ptarmicae. Desm., Ann. Sci. Nat., 

 Ser. iii. vol. xi. p. 3G1 ; Eehm, Krypt.-Fl., Hyster., p. 75, figs. 

 1-5, p. 63; Sacc, Syll., ii. n. 5559. 



Gregarious, innate, black, |— J mm. across, circular or ellip- 

 tical, rather soft when moist, cells of excipulum small, very 

 compact, external ones hlackish-olive, dehiscing by an elon- 

 gated or stellately radiating slit; asci cylindric-clavate, most 

 frequently containing only 2 spores ; spores elliptic-oblong, 

 or very slightly clavate, straight or very slightly curved, 

 smooth, ends obtuse, hyaline, 1-septate at maturity, 10-14 x 

 5-6 /x ; paraphyses filiform, slender, septate, slightly thick- 

 ened, branched, and coloured above. 



Labrella ptarmicae, Desm., Crypt. Fr., exs. n. 189. 



On living leaves of Achillea ptarmica, forming very minute 

 black spots. 



Spermogonia. Perithecia almost plane, shield- like, circular 

 or very broadly elliptical, 300 /x diam., not provided with a 

 pore for dehiscence, consisting of sinuous, brownish cells 

 forming a pseudo-parenchyma; sporidia ovate-oblong, 10 x 

 6—7 ft ; contents cloudy, sometimes indistinctly divided 

 into two portions, hyaline, supported on short, cylindrical 

 basidia. 



Labrella ptarmicae, Desm., exs. n. 149 (in part). 



Leptothy Hum ptarmicae (Desm.) Sacc, Mich., ii. p. 114; 

 Sacc, Syll., iii. n. 3379. 



On stems of Achillea ptarmica. 



Schizothyrium aquilinum. Rehm, Krypt.-Flor., 

 Hyst., p. 75. 



Gregarious, covered at first by the adherent epidermis 

 rounded or elongated, deformed and rugulose, black, opaque 



