Editing Downy mildew (section)

=== Floricolous species ===
[[File:Peronospora violacea comparison.jpg|thumb|Flowerheads of ''[[Succisa pratensis]]'', infected (right) and uninfected (left) with the floricolous downy mildew ''[[Peronospora violacea]]''.]]

One monophyletic clade of ''[[Peronospora]]'', known as the ''floricolous downy mildews'', only cause symptoms in the flowers of their hosts.<ref name="Thines">{{cite journal | vauthors=((Thines, M.)), ((Kummer, V.)) | journal=Mycological Progress | title=Diversity and species boundaries in floricolous downy mildews | volume=12 | issue=2 | pages=321–329 | date=1 May 2013 | issn=1861-8952 | doi=10.1007/s11557-012-0837-7| bibcode=2013MycPr..12..321T }}</ref> Infection is systemic,<ref name="Thines"></ref> with [[hyphae]] produced at low densities in the host xylem.<ref name="Contribution">{{cite journal | vauthors=((Horáková, J.)), ((Skalický, V.)) | journal=Česká Mykologie | title=Contribution to the ecology of Peronospora violacea Berk. | volume=43 | issue=1 | pages=13–29 | date= 1989}}</ref> This clade is known from hostplants in the [[Asteraceae]], [[Campanulaceae]], [[Dipsacaceae]], [[Lamiaceae]], and [[Orobanchaceae]].<ref name="Thines"></ref>

One floricolous species, ''[[Peronospora violacea]]'', causes its host ''[[Succisa pratensis]]'' to produce longer, pinker petals,<ref name="Field Guide">{{cite web | vauthors=((Dalzell, J.)) | year=2024 | title=Pathogens in Grassland | website=Field Guide to Plant Pathogens | url=https://plantpathogens.neocities.org/habitats/grassland | access-date=19 December 2024}}</ref> and abort its [[anthers]].<ref name="Contribution"></ref> Other authors report that on the same host it causes the host [[petals|corollas]] to be brownish and dead-looking.<ref>{{cite book | vauthors=((Chater, A. O.)), ((Woods, R. G.)), ((Stringer, R. N.)), ((Evans, D. A.)), ((Smith, P. A.)) | date= 2020 | title=Downy Mildews (Peronosporaceae) and White Blister-Rusts (Albuginaceae) of Wales = Llwydni Gwlannog (Peronosporaceae) a Rhydau-Pothelli Gwynion (Albuginaceae) Cymru | publisher=A.O. Chater | isbn=978-0-9565750-4-3}}</ref>