536 MICROSCOPIC FUNGI. 



Peronospora Hyoscyami, De By. Heneane Mould; 

 feri.ile threads thick, 5-S_ times dichotomous, brandies patent, 

 attenuated, straight or slightly curveJ, the ultimate forming a 

 very obtuse angle, divergent, short, subulate, straight, acute ; 

 conidia small, ellipsoid, very obtuse; epispore pale violaceous. — 

 On common Henbane. Market Deeping. 



Peronospora entospora, B. and Br. Fleabane Mould ; 

 fertile threads simuie, clavate, surmounted by a crown of apiculi 

 bearing the ellipsoidal conidia, each of which is papillate at the 

 apex, endochrome granular; ongouia yellowish, subglobose, 

 -tuberculate. — On Erigeron Canadense. 



Peronospora Trifoliorum, De By. Clover Mould; 

 feriile threads ccespitose, equally or unequally 6-7 times dicho- 

 tomous, rarely trichotomous ; ultimate branches subulate, acute, 

 slightly curved ; acrospores ellipsoid, very obtuse ; membrane 

 with a slightly violaceous tint ; oospores large ; epispore brown. — 

 On Lucern 0Ledkago sativa). Highgate and Hampstead, ISG^. 



Peronospora grisea, Ung. Veronica Mould; fertile 

 threads erect, fasciculate, grey, 5-7 times regularly dichoto- 

 mous ; branches gradually attenuated ; primary oblique, erect, 

 others spreading, iiexuose_; ultimate mostly unequal, slightly 

 arcuate; acrospores ellii'snid or ovoid, obtuse; membrane pale 

 and dirtv violet. — On leaves of Veronica beccabunga. May, 184:5. 

 (Plate X. fig. 213.) 



Peronospora calotheca, De Bary. Flocci slender, 7-9 

 times dichotomous; primary branches oblique, erect, the resti 

 patent, squarrose, slender; uliiniate ramuli short, straight, or 

 curved; acrospores elliptical; oospores globose; epispore bay- 

 brown, minutely reticulated. — On Galium Jparine. 



Peronospora arborescens, Berk. Poppy Mould ; fer- 

 tile threads slender, erect, 7-10 times dichotomous above; 

 branches more or le&s flexui^se, squarrose, spreading, gradually 

 attenuated ; ultimate ramuli shortly subulate, more or less arcuate; 

 acrospores very small, subgiubose ; membrane scarcely violaceous. 

 — On the Cora Poppy. June. Couimon. 



Peronospora SehleidGniana, De By. (P. destructor, B.) 

 Omion Mould ; fertile threads robust, erect, not septate, 

 branched alternately; ultimate ramuli forked and uncinate or 

 divaricate ; acrospores seated on the tips of the ultimate ramuli, 

 obovoid or nearly pear-shaped, attenuated at the base; mem- 

 brane of a dirty violet-colnur. — On the leaves of various species 

 of Allium. Often plentiful. (Plate XIII. fig. 263.) 



