Fig. 3.15(a–t)Morphology of Peronosporaceae s. lat.
(a–c) Drawings ofPhytopythium ostracodesshowing
papillate (a) and proliferating (b) sporangia and
apleurotic oogonium with thick-walled oospore (c).
From Plaats-Niterink ( 1981 ). (d,e) Drawings ofHalo-
phytophthora vesicula.Mature (d) and discharging (e)
sporangium showing large transient elongate vesicle
characteristic of this species. (f–j) Drawings ofPhy-
tophthora spp. Non-papillate sporangium of Phy-
topthora sojae(clade 7) (f). From http://microbe.
eolchina.org. Aerial sporangiophore ofPh. infestans
(g) bearing deciduous (caducous) papillate sporangia
(h) from which zoospores (i) are released. Young (j)
and mature (k) oogonia ofPh. erythrosepticashowing
collar-like amphigynous antheridium (k) and mature
oospore with central ooplast (k). Adapted from Webster
( 1970 ). (l–t) Drawing ofdowny mildews in Peronospor-
aceae.Branched sporangiophores with terminal spor-
angia ofPeronosclerospora sorghii(GDM clade)on
millet (l) and its mature thick-walled oospore (m).68 G.W. Beakes et al.