Clavulina rugosa

Our study group formed and began surveying the forests for fungi in December of 2019. From that first foray through March we found Clavulina rugosa, and we called it "our friend." It didn't matter what forest we were in, but if there was Douglas Fir, Pseudotsuga menziesii, nearby this was fruiting along the forest floor.

Calvulina rugosa is a white club shaped coral fungi that grows in the duff or soil of the forest floor. It is mychorrizal with Douglas fir and other conifers. We have seen this prolific mushroom fruiting all winter long and in a very wide geographic range. I initially discovered it in December 2019, before I knew how to key anything out. This was a tough start to identify this mushroom, because of all the similar coral shaped mushrooms like Ramariopsis, Lentaria, Ramaria, Tremellodendropsis and others. What makes it even harder is most books only mention this mushroom in passing, in the comment section, so you have to piece clues together while searching for a name. I was not the one who eventually was able to name this mushroom, but it was the first mushroom I learned about, and it stuck with me because of how often we saw it on our adventures.

I diligently gathered samples of this mushroom for months, before finally getting a spore print off of a specimen. Initially I had taken over my dining room table to ID mushrooms. There were egg cartons and index cards full of specimens offering spore deposits while I wrote down notes on each one. The day after I collected the mushroom, I looked under the bowl, and there on my glass slide was a nice white spore deposit of Clavulina rugosa. These spores were tiny! They were about 12x14 um and sort of globose-ish, smooth and have a tiny apiculus (the little point at the end of the spore, look at the x1000 image) where the spore was connected to the 2 sterigmata basida. I never got a chance to section the mushroom to see the basidia, but that is something I plan to do as soon as I see our friend again.

Classification:​
Fungi
Basidiomycota
Agaricomycetes
Incertae sedis
Cantharellales
Hydnaceae
Clavulina

Description:
White club fungi with blunt tips, sometimes wrinkled looking, branching only a few times, and may look like antlers
Base is not separate from the upper branched part
Spore print is white
Iron salts give no reaction on branches
Microscopic features
2-sterigmate basidia, 9 um long, with a devils horn look to the sterigmata
spores are about 12x14 um and almost globose, with a visible apiculus at one end.
​clamp connections present

Resources:
http://www.speciesfungorum.org/Names/NamesRecord.asp?RecordID=356704
https://www.mushroomexpert.com/clavulina_rugosa.html

Arora, David (1986). Mushrooms Demystified, 2nd ed.
Largent, David & David Johnson. How to Identify Mushrooms to Genus III: Microscopic Features
Siegel, Noah and Christian Schwarz (2016). Mushrooms of the Redwood Coast: A Comprehensive Guide to Fungi of Coastal Northern California