at FAYETTE, row'A. 1 1 



The appendages are about equal to the diameter of the perithecia in 

 Syringa and Viburnum and twice as large in Ulmus and Corylus. The 

 mycelium is most noticeable in Viburnum. The perithecia vary in size 

 from 65 u in Corylus to 100 u in Viburnum. 



4. M. Grossui.ari.-k, (Wallr.) Lev. 



Amphigenous. Mycelium thin or rather dense, white, persistent. Perithecia 

 scattered. 75 120 u . reticulations about 15 u\ appendages 10-20, once or twice as long 

 as the diameter of the perithecium , hyaline or tinted at the base, very conspicuously 

 4-6 times dichotomously forked, with straight, obtuse, digitate branchlets, asei 3 5, 

 sporidia 4.-6, variable, 15 30 11 long. 



On Sambucus Canadensis. 



I find no record of this in Iowa lists. It may have been included 

 with M. Alni, but the appendages are very different. 



5. M. QUERCINA, (Schw. ) Burrill. 



Epiphyllous, hypophyllous, or amphigenous. Mycelium abundant, rather 

 thin and pruinose. forming orbicular patches or spreading over the whole surface of 

 the leaf; perithecia abundant, scattered, varying from 80-140 u , reticulations evident, 

 small, and irregular; appendages less than 20, varying in length from lessthan,to4 

 or 5 times, the diameter of the perithecium, tinted at base, smooth or sometimes 

 roughened, usually regularly s-6 times dichotomous, branches short and tips strongly 

 recurved, but presenting many curious and ornate variations caused by the more ex- 

 tended or unequal growth of some of the branches; asci 3-8, often rupturing by slight 

 pressure; sporidia 4-8, variable, usually large, 20-30 11 long. 



On Quercus alba and (). rubra. 



We have six oaks here, and this form doubtless occurs 011 other 

 species than those named. 



Besides the species described, conidiiferous specimens were collected 

 on the following hosts: 



/ — Rudbeckia laciniata. 2—Cacaliatuberosa. 3— Sisymbrium officinale. ./--■■ 

 Helen inm antumnale. 5 —Nasturtium sylvestre. b—Potentilla Norvegica. j—Epilob- 

 ntm coloratum. o — Phlox sp. ro—Ldctua Canadensis. n—Physostegia Vtrgin- 

 iana. T2 —Ranunculus abortTvus. rj--t 'hrysanthemum (cultivated). 



Number ten had immature perithecia also. Erysiphe Cichorace- 

 ar/im, DC. is reported elsewhere on numbers two and four. The form 

 on number seven may be Sphaerotheca Epilobi ', (Link/), which is found 

 elsewhere, the perithecia seldom developing, No Erysiphece are re- 

 ported on the other numbers so far as I know. Chrysanthemum was 

 attacked and killed after the plant was taken into the iiou.se in Septem- 

 ber. 



The following hosts occur here, known to bear species of Erysiphece 

 elsewhere, which I have not found here: 



Two species of Rhus, three of Desmodium, three of Vicia, Celtis occidentklis, 

 Menispermum Canadense, Symphoricarpos Occident 'alis and. a few cultivated ('utalpaw ' 



These were all carefully examined, and yet I suppose that the 

 parasites, though surely rare, if present, this year, may be plentiful in 

 other years; and I have given them so that any one who is interested 

 may search these hosts. There are a few other plants found here which 

 bear Erysiphece in California, or in eastern or southern states. These 

 I have omitted. 



In instances where a species has been transferred from one genus to 

 another, I have given the name of the botanist who made the change 

 after that of the one who first named the plant. It is somewhat of a 

 question as to whether this should be done, but certainly there is no 

 injustice in it as the first name is retained. 



