Phytophthora pluvialis

Name and publication

Phytophthora pluvialis Reeser, Sutton and Hansen (2013)

Reeser P, Sutton W, and Hansen E. 2013. Phytophthora pluvialis, a new species from mixed tanoak-Douglas fir forests of western Oregon, U.S.A. North American Fungi 8: 1–8.

Corresponding author: Paul Reeser,


from Reeser et al. (2013)




refers to the rain-associated canopy drip from which many isolates were recovered


Type: UNITED STATES OF AMERICA, from baited rainwater near Brookings isolated in Oregon (N42.11185, W-124.25657) in February 2008; dried culture from OSU LC-9.2-020508

Ex-type: MYA-4930

Sequences for ex-type in original manuscript: LC-9.2-020508 = ITS rDNA KC529657, Cox 2 KC529656

Ex-type in other collections

MYA-4930 = 60B3 (Yang)

Molecular identification

Voucher sequences for barcoding genes (ITS rDNA and COI) of the ex-type (see Molecular protocols page)

Phytophthora pluvialis isolate LC-9.2-020508 ITS rDNA KC529657

Sequences for ex-type in other sources
Position in ITS phylogenetic tree

Clade 3a

Morphological identification

adapted from Reeser et al. (2013)

Colonies and cardinal temperatures

Colony morphology on PDA, V8A, MEA with petaloid pattern. Minimum growth temperature 5°C, optimum 20°C, and maximum 25°C.

Conditions for growth and sporulation

Sporangia and hyphal swellings formed in water.

Asexual phase

Sporangia semipapillate, sometimes bipapillated; partially caducous with medium-length pedicels (7–22 μm); ovoid or slightly irregular (53–67 L x 39–45 W μm); originated in unbranched or simple sympodial sporangiophores. Hyphal swellings globose, catenulate and lobate, intercalary with radiating hyphae. Chlamydospores absent.

Sexual phase

Homothallic. Oogonia smooth-walled, globose (29–35 µm diam); antheridia amphigynous; oospores aplerotic (26–30 µm diam).

Most typical characters

Phytophthora pluvialis is characterized by the presence of semipapillated, partially caducous sporangia with medium-length pedicel, and the presence of globose, catenulate, lobate, and radiating hyphal swellings.

Hosts and distribution

Distribution: North America (USA: OR), New Zealand
Substrate: needles, twigs
Disease note: needle cast, shoot dieback, stem lesions
Host: in association with twig cankers of Notholithocarpus (Fagaceae), Pinus radiata, Pseudotsuga menziesii (Pinaceae)

Retrieved February 01, 2018 from U.S. National Fungus Collections Nomenclature Database.

Additional references and links

Fact sheet author

Z. Gloria Abad, Ph.D., USDA-APHIS-PPQ-S&T Beltsville Laboratory, United States of America