Arthur: Uredinales of Costa Rica 135 



luxuriant and the leaves much larger than on shoots of slower 

 growth. Such preference seems to be common for rusts on 

 shrubs and trees. 



69. Puccinia mitrata Sydow (on Lamiaceae) 

 Salvia polystachya Ort., San Jose, Jan. 3, 191 6, ii, III, 348. 



The species occurs also in Guatemala and southern Mexico. 

 The present collection, the only one known from Costa Rica, has 

 the characteristic, thick-walled teliospores of the species, which is 

 a close relative of P. farinacea. The beginning stages in the 

 life cycle are not known. 



70. Puccinia impedita Mains & Holway sp. no v. (on Lamiaceae) 

 Salvia hyptoidis Mart. & Gal., Heredia, Dec. 17, 1915, II, 264.) 



San Jose, Dec. 26, 191 5, II, III, 297 (type) ; Orotina, Dec. 



31, 1915, II, 340. 

 Salvia occidentals Sw., Orotina, Dec. 30, 191 5, II, 326. 

 Salvia tiliae folia Vahl, Tres Rios near San Jose, Jan. 17, 191 6, 



II, iii, 441. 



Uredinia hypophyllous, scattered, round, 0.1-0.5 mm. across, 

 early naked, pulverulent, cinnamon-brown, ruptured epidermis 

 evident; urediniospores oblate-sphaeroid, 18-23 p broad by 16- 

 19/x. long, or globoid, 16-23 fi in diameter; wall cinnamon-brown, 

 1— 1.5 fi thick, moderately echinulate, the pores 2-3, approximately 

 equatorial or slightly subequatorial. 



Telia hypophyllous or caulicolous, scattered, on the leaves 

 round, 0.2-0.4 mm. in diameter, on the stems crowded or coales- 

 cent, 2-12 mm. in length, early naked, pulvinate at first, becom- 

 ing pulverulent, blackish-brown, ruptured epidermis inconspicu- 

 ous ; teliospores broadly ellipsoid, 24-32 by 30-50 fx, rounded at 

 both ends, not constricted at septum ; wall dark chestnut-brown, 

 thick, 3-5 fx, thicker over germ pore as a yellowish umbo, 5-9 

 very finely and inconspicuously verrucose ; pedicel long, two to 

 three times length of spore, the wall usually firm and thick, 

 r. 5-2.5/*. 



The species is related to P. salviicola Diet. & Holw., where it 

 has heretofore been listed, but which is now believed to be a 

 more northern form, not reaching to Central America. It also 

 resembles P. caulicola Tracy & Gall., but the teliospores are con- 



