Phytophthora crassamura

Name and publication

Phytophthora crassamura Scanu, Deidda & Jung (2015)

Scanu B, Linaldeddu BT, Deidda A, and Jung T. 2015. Diversity of Phytophthora species from declining Mediterranean maquis vegetation, including two new species, Phytophthora crassamura and Phytophthora ornamentata sp. nov. PLoS ONE 10 (12): 1–24 (pg. 24).

Corresponding author:


from Scanu et al. (2015)




refers to the thick-walled oospores (‘crassa’ = ‘thick’ and ‘mura’ = ‘wall’)


Type: ITALY, Sardinia. Isolated from rhizosphere soil of a dying Juniperus phoenicea tree. Collected: B. Scanu, 2012; CBS H-22392 (holotype, dried culture on CA, Herbarium CBS-KNAW Fungal Biodiversity Centre)

Ex-type: CBS 140357 = PH138 (ex-type culture)

Sequences for ex-type: Phytophthora crassamura isolate PH138: ITS rDNA KP863493, cox1 KP863485

Ex-type in other collections

CBS 140357 = P20138 (WPC), Ph138 (Scanu), CPHST BL 150 (Abad), 66D1 (Yang)

Molecular identification

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

Phytophthora crassamura isolate CPHST BL 150A (= P20138) ITS rDNA MG865481, COI MK493474

Sequences for ex-type in other sources
  • NCBI: Phytophthora crassamura Ph138
  • NCBI: Phytophthora crassamura isolate CPHST BL 150A
  • Phytophthora DATABASE: Phytophthora crassamura
  • EPPO-Q-bank: Phytophthora crassamura
  • BOLDSYSTEMS: Phytophthora crassamura
Position in ITS phylogenetic tree

Clade 6b

Morphological identification

adapted from Scanu et al. (2015)

Colonies and cardinal temperatures

Colony morphology after 7 days on PDA and CMA with no distinct pattern, and on MEA faintly petaloid. Minimum growth temperature 5°C, optimum 25°C, and maximum 33°C.

Conditions for growth and sporulation

Phytophthora crassamura produces sporangia in both solid media (CA) and more abundantly in liquid culture (soil extract water) after 24 hours of incubation at 20°C.

Asexual phase

Sporangia nonpapillate, persistent; ovoid and obpyriform, sometimes with a distorted and pointed apex (48–73 x 23–52 µm); with external and internal in extended and nested proliferation, and originated terminally on simple, mostly unbranched sporangiophores. Hyphal swellings globose, elongated, and catenulated. Chlamydospores absent. 

Sexual phase

Homothallic. Oogonia smooth-walled (35–52 µm diam); antheridia predominantly paragynous (8–16 x 8–14 µm); oospores aplerotic (28–45 µm diam).

Additional specimen(s) evaluated

Phytophthora crassamura ex-type CPHST BL 150, duplicate of P20138 World Phytophthora Collection – California, USA, duplicate of ex-type CBS 140357

Hosts and distribution

Distribution: Europe (Italy, Turkey)
Substrate: collar; rhizosphere soil
Disease note: collar rot, decline
Host: Juniperus phoenicea (Cupressaceae), Picea abies (Pinaceae), Castanea sativa (Fagaceae)

Retrieved January 29, 2018 from U.S. National Fungus Collections Nomenclature Database.

Additional references and links

  • Phytophthora DATABASE: Phytophthora crassamura
  • EPPO-Q-bank: Phytophthora crassamura
  • SMML USDA-ARS: Phytophthora crassamura
  • EPPO Global Database:  Phytophthora crassamura
  • CABI Invasive Species Compendium: Phytophthora crassamura
  • Encyclopedia of Life (EOL): Phytophthora crassamura
  • Index Fungorum (IF): Phytophthora crassamura
  • Plantwise Knowledge Bank: Phytophthora crassamura

Fact sheet author

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