AECIDIUM-FOltMS. 411 



Aec. Peckii De Toni and Aec. oenotherae Mdiit. On leaves of species 

 uf Oenothera. 



Aec. sambuci Sdiwein. On leaves and stems of Samhun/s. 



Aec. ceanothi Ell. et Kell. 



Aec. abundans Peek. On species of Symphoricarpus. 



Aec. cephalanthi Seym. On Cephalantlms occidentale. 



Aec. erigeronatum Schwein. On many species of Erigeron. 



Aec. asterum Schwein. On species of Aster and SoUdago. 



Aec. polemonii Peck. On Polemonium and Phlor. 



Aec. apocyni Sclnvein. On leaves of Apocijinim. 



Aec. Jamesianum Peek, and Aec. Brandegei Peck. On leaves of species 

 of Aschpiaii. 



Aec. myosotidis Burr. On leaves of Mi/usotis renia, etc. 



Aec. plantaginis C'es. On leaves of species of Plantago in Europe and 

 America. 



Aec. pentastemonis .Sehwein. On sjjecies of Pentstemon. 



Aec. giliae Peck. 



Aec. lycopi (ierard. On leaves and stems uf Lticopnis cnropoevit. 



Aec. iridis (4erard. 



Aec. macrosporum Pt-ek, and Aec. smilacis Srhwein. On species of 

 Smila.i-. 



Peridermium. 



Peridermium pini (Willd.)^ is found on pine-trees in Euro])e, 

 Britain, iuul United States. A teleutospore-stage of this has not 

 as yet been identified, although a very similar species {Pcri- 

 (hrmmvi Cornui Eostr. et Kltb.), also occurring on the bark of 

 pines, has been proved to have as its teleutospore-forni Cronartium 

 asdepiadeum.^ 



The mycelium of rrr'ulrrmium ijiui lives intereelluhiily in 

 the rind, bast, and wood of Finns sylvcdris, F. Laricw, P. 

 halependa, P. maritima, and P. montana. It lives and extends 

 through the stem for years, attacking the living cells and 

 absorbing nutriment from them by little haustoria. The cells 

 of parenchymatous tissues are those most generally attacked, 

 and the mycelium has been found to penetrate along the 

 medullary rays to a depth of 10 cm. into the wood-mas.s. 

 The cells of attacked parts lose their normal content including 

 starch, and secrete crude turpentine in such quantity as t<» 

 completely permeate their walls, and even to form drops. In 

 this way portions of the wood become completely saturated 



^ R. Hartig, Wkhtvje Krankheiten d. Waldhiiumein. 

 -Klebahn, Berichtc d. dentuch. hotav. Oeselfsrfiaft, 1890. 



