Host Plants - Westcott's Plant Disease - page 582

L EAF S POT . Cercospora oxalidiphila, WI;
Phyllosticta guttulatae, VT to NJ, IN, WI,
Ramularia oxalidis, NE, NH, NM, OR, PA,
TN, VT; Septoria acetosella, NY; tar spot,
Phyllachora oxalina, DE, ME, VT.
N EMATODE , Root Knot. Meloidogyne spp.
N EMATODE , Stem. Ditylenchus dipsaci, NY.
P OWDERY M ILDEW . Microsphaera russellii,ME
to WV, KS, MN, WA.
R OT , Root. Thielaviopsis basicola, CT.
R UST . Puccinia andropogonis (0, I), OK, TX, II,
III on Andropogon ; P. oxalidis (II, III), FL,
GA, LA, MS, NM, SC, TN, TX, WI;
0, I on mahonia; P. sorghi (0, I), IN, IA, KS,
MI, MS, ND, OK, SD, TX; II, III on corn and
Euchlaena .
S MUT , Seed. Ustilago oxalidis, CT to MS, OH,
TX, WI.
V IRUS . Beet Curly Top, TX; Tomato Ringspot,
PA; Tomato Spotted Wilt, PA; Shamrock
Chlorotic Ringspot.

Oregano, Sweet Marjoram (Origanum)

R UST . Puccinia menthae, CA, FL.

Osage-Orange (Maclura)

B LIGHT , Leaf. Sporodesmium maclurae,MO,
SC, TX; Botrytis cinerea, OR, gray mold on
stems.
D AMPING -O FF . Pythium ultimum, NE; Rhizoc-
tonia solani, NE.
L EAF S POT . Cercospora maclurae, AL;
Ovularia maclurae, AL, LA, TX;

Phyllosticta maclurae, MO, NJ.
M ISTLETOE . Phorodendron tomentosum, TX;
P. serotinum (flavescens), TX.
R OT , Root. Phymatotrichum omnivorum, TX.
R UST . Cerotelium fici (II), SC to FL and TX.
W ILT . Verticillium sp., CT.

Osier, Basket-Willow (Salix) Oxydendron (Sourwood, Sorrel-Tree)

C ANKER . Cryptomyces maximus, Blister; Valsa
salicina, Twig, Branch, CA, IA.
R UST , Leaf. Melampsora abieti-capraearum,
NY, PA.

B LIGHT , Twig. Sphaerulina polyspora, NC.
L EAF S POT . Cercospora oxydendri, AL, MS, TX,
WV; Mycosphaerella caroliniana, GA, NC,
TX, WV.
R OT , Root. Phymatotrichum omnivorum, TX.
R OT , Wood. Poria punctata, WV.

Osoberry (Osmaronia)

Pachistima

L EAF S POT . Cylindrosporium nuttallii,CAto
OR, WA; Gloeosporium osmaroniae,WA.
P OWDERY M ILDEW . Phyllactinia corylea, OR. L EAF S POT . Mycosphaerella pachystimae, ID.

Owls Clover (Orthocarpus) Pachysandra (Japanese-Spurge)

Ground Cover

L EAF S POT . Ascochyta garrettiana, OR, UT.
R UST . Cronartium coleosporioides (II, III), CO,
ID, UT; 0, I on pine.

B LIGHT , Leaf; Stem Canker. Volutella
pachysandrae ( Pseudonectria
pachysandricola ), CT, DE, NJ, NY, PA, VA;
Sphaeropsis sp., tip blight, secondary.
L EAF S POT . Gloeosporium sp., VA; Phyllosticta
pachysandrae, NY, NC, PA, VA; Septoria
pachysandrae, FL, TN.

Oxalis (Wood-Sorrel)

B LIGHT , Gray Mold. Botrytis cinerea, AK.