THE ERYSIPHEI OF THÉ UNITED STATES. ` 11 
E 
solely differing in far more evidently monadelphous stamens. Be it not 
forgotten, that in Acacia we have not on ly a remarkable diversity of form 
and dehiscence of the fruit, but we find also in the section Vachelliaa 
legume * filled with pulp,” to use the expressions of the founders of that 
now abolished genus (Wight t and Arnott, Prodr. Flor. Penins. Ind. Or. 
272). To me, at least, it appears that within the same family, and more 
p in elosely-related — an equitable value must be ceres 
o their characteristics, and that s, which are not regarded of gene 
iesita in one case, cannot receive a higher value in the definition re 
allied genera. If the presence of a pulpy covering of the seeds in reali 
can separate Pithecolobium as a genus from Albizzia, then all the Austra- 
edi and many Indian, species of the former must be relegated to the 
latte 
THE ERYSIPHEI OF THE UNITED STATES. 
By M. C. Cooke, M.A., AND C. H. PECE. 
The following enumeration of the species of North American Erysiphei 
more complete investigation of the forms recorded by Schweinitz, some of 
which have not as yet come under our notice. ‘This must, therefore, be 
accepted ra hae as a contribution towards a synopsis of the species chin 
an exhaustive catalogue. Further information is still required, even for 
C 
re. 
1. Podosphera Kunzei, Lev. ; Cooke, Handbook Brit. Fungi, n. 1916. 
—On leaves of Prunus Cerasus and Spiræa salicifolia. ‘New York 
(C. H. P. n. 162). 
2. P. biuncinata, C. and P.  Epiphyllous. Conceptacles globose, 
minute, scattered. Appendages 6—10, from three to five times as ‘long as 
the diameter of the sob ebateós farcate at the tips and "siege extre- 
mities obtuse, ultimate ramuli Ves di subdivided.—On leaves of Witch 
azel, Hamamelis virginica. Sanc A Oe, ee 144). 
3. Spherotheca Castagnei, Lev. ; S Docks, Handbook, n. 1911.— Zrysiphe 
J'liginea, Schwz. Fung. Am. Bo r. n. 2469 : var. C, on Sanguisorba cana- 
densis, Carolina (Schwz. ); on Agrimonia Eupatoria, New Baltimore, N. Y. 
); on Geum album, New York (C. H. P.) ; on Spiræa opuli- 
folia, New rpm qid N. Y. (C. H. P.) : var. G, on Bidens con i 'Tyre, 
NX (C H. F}: grt on Brunella bes ssir Buffalo, N. Y. (C. H. P). 
4 nd 
i a se a, C: mphigenous. Mycelium ef- 
fused, Srkokensil, vübpereisténi: Duos minute, globose, counted. 
endages few, interwoven, eolourless.—On both surfaces of leaves of 
Rhus glabra, Albany, N. Y. (C. H. P. n. 150), New York (W, W. D. n 
47).—Habit and character of mycelia "I distinct from S. pannosa. 
The colourless appendages will not permit of its being aa ea d- with 
S. Castagnei. Sporidia '0007— 0008 i in. x :0004 in 
5. Phyllactinia guttata, Lev. ; ern Heated, | n. 1912.— Erysiphe 
guttata, Schwz. Fung. Am. Bor. n. 2476 6.—On leaves of Corylus, Carolina 
. (M. A. CO); on leaves of ess ‘terrulata, Celastrus scandens, Carpinus 
americana, etc., Albany, N. Y. (C P x18 
6. Uncinula Bivone, Lev. ycelium wahh evanescent. Con- 
ceptacles generally scattered, minute. Sporangia 4, subglobose, with 2 
