last update October 26, 1999
The mycorrhizal status of Adenostoma fasciculatum, the dominant shrub in California chaparral, has been unclear. In two typical , nearly monospecific stands, A. fasciculatum was found to have arbuscules and intercellular hyphae. Antisera detected hyphae of the arbuscular mycorrhizal (AM) fungal genera Acaulospora, Glomus, and Scutelluspora, although we found only spores of Glomus. Some roots had partial sheaths and inter- and intracellular septate fungi without indications of root necrosis. Ectomycorrhizal root tips were also found , including Cenococcum and other unknown taxa. Sporocarps of Hygrophorus, and Coritnarius were found in the stand, with no other EM or arbutoid mycorrhizal plants nearby. These observations indicate that A. Fasciculatum forms mycorrhizae with AM, septate, and EM fungi, but often fails to form easily recognizable mycorrhizal structures.