Rhytismatales

© Matthew Koons

Danny’s DNA Discoveries – Rhytismatales of the PNW
by Danny Miller

Introduction

The Leotiomycetes are the inoperculate class of ascos, where the ascii do not have a lid, but instead have a pore at the top that the spores escape from. This is difficult to see without a quality microscope, but the species in the class are usually tiny cup fungi (maximum size <1cm across) growing on wood, as well as the earth tongues (club fungi with a differentiated head). In contrast, the Pezizomycetes contain true truffles, morels and false morels, the larger cup fungi, and tiny cups that do not grow on wood (although there are exceptions). Other classes of ascos exist as well with more cups, truffle-like fungi, and carbonaceous fungi. My ITS tree cannot show the orders holding together, but a 15-gene study confirms where I have placed these species.

The Rhytismatales order contains a wide variety of fungal forms:

Spathularia (Cudonia, Pachycudonia) - earth tongues with irregular hemispherical heads or spathulate heads.

Calycina ('Bisporella' misapplied) - minute yellow cups on wood

Coccomyces, Colpoma, and Rhytisma - black tar spots on leaves and wood

Discocania and Triblidium - roundish minute black fruitbodies erumpant from conifer wood

Phialina - yellow eyelash cups on leaves

abundant common uncommon rare - colour codes match my Pictorial Key and are my opinions and probably reflect my bias of living in W WA. Rare species may be locally common in certain places at certain times.

Spathularia (Cudonia, Pachycudonia)

Traditionally, Cudonia are earth tongues that have irregularly spherical heads and Spathularia have spathulate heads. A multi gene study found that Spathularia flavida and allies could be considered separate from Cudonia only if Spathularia velutipes and allies were considered to be in a genus of their own, Spathulariopsis. Because some species elsewhere on the planet do not conform to the traditional shapes, the authors recommend that all these species be referred to by the oldest name, Spathularia. They also showed that Pachycudonia does not need its own genus separate from Cudonia.

'Cudonia' circinans EU - with an irregularly round yellow-tan head. One WA sequence matches EU sequences. It is also found in AK. Perhaps it is a more northern species.

'Cudonia' confusa EU - difficult to differentiate from C. circinans, thus the name. One OR sequence matches many EU sequences. It is also found in CA. Perhaps it is a more southern species.

'Cudonia' monticola WA (=Pachycudonia monticola) - the head is differently coloured, pinkish-cinnamon or darker brown, but perhaps most easily recognized as our spring species.

'Cudonia' grisea WA - The stem is dark grey. The description says the head might be dark grey too, but our sequenced collection had a yellow-tan head. We don't have the type sequence yet, but I assume this is it. If not, we need to figure out what this is.

Spathularia 'flavida PNW01' - with a yellow spathulate head. Our WA and BC sequences (along with a PQ and Japanese sequence) are 7 bp different than EU and Chinese sequences of S. flavida, so it should be investigated if ours is a distinct species. One close EU sequence was identified as Spathularia neesii EU, so it should also be investigated if that could be the name of our fungus.

An ochre species of Spathularia has been found in WA and needs to be sequenced to see what it is.

Cudonia circinans © Christin Swearingen (from AK), C. monticola © Steve Ness, Cudonia grisea © Yi-Min Wang

Spathularia 'flavida PNW01' © Matthew Koons, unsequenced ochre Spathularia © Andrew Parker

Calycina (Bisporella)

Calycina citrina EU (Bisporella citrina misapplied) - by far our most common minute yellow cups on wood, lacking a stem and any hairs. A multi-gene study placed this species in Calycina instead of Bisporella. Two WA sequences match many EU sequences.

Calycina claroflava EU (Bisporella sulfuina misapplied) - similar but growing parasitically on Sordariomycetes (black pimpled crusts) that may be found on the same hardwood log. This is the species reported from the PNW, but so far we've only sequenced C. citrina. We need collections on logs with a black pimpled crust to see what they are, although the log that one of our C. citrina collections was growing on shows some black dots of something (see photo). Perhaps smaller, more translucent cups will indicate this species. We need collections.

Calycina citrina © Yi-Min Wang

Coccomyces, Colpoma, and Rhytisma

Rhytisma 'punctatum PNW01' - speckled black patches on maple leaves surrounded by leaf discolouration. PNW sequences differ by 3% in ITS from ENA sequences, and we don't have any EU type area sequences, so our species might need its own name.

Rhytisma 'salicinum PNW02' - small black spots on willow leaves, with both an asexual and a sexual stage. We have two ID sequences purporting to be this, but they are different species. We have no EU type area sequences to compare. I don't get strong support for this being inside Rhytisma in my ITS only tree. I'd like to see more genes confirm the genus of this species.

Rhytisma 'salicinum PNW03' - see PNW02. It is in the same genus as PNW02, but that might not be Rhytisma.

Rhytisma cf acerinum EU - reported from the PNW. We have EU type area sequences, but no local sequences yet. Presumably it is on maple leaves like PNW01. This is the type species of the genus.

Rhytisma cf americanum NY - can also be on maple. It was reported from the PNW. We have a bunch of ENA sequences within 4 bp of each other, but no local sequences yet.

Rhytisma arbuti CA - on madrone leaves from CA. This has been reported from the PNW as well, but we have no DNA from anywhere yet.

All Coccomyces species have their real genus called into question. We don't have any DNA of the type species, Coccomyces coronatus, and the species we do have seem paraphyletic in several places in the tree.

'Coccomyces' arbutifolius BC - tiny black spots on madrone leaves. No DNA yet.

'Coccomyces' 'dentatus PNW02' - cool hexagonal black spots on Oregon grape leaves. This is a species complex around the world on different leaves, so our species likely needs its own name. I don't have any EU type area sequences.

'Coccomyces' cf arctostaphyli EU - on kinnikinnik leaves, no ITS DNA available

'Coccomyces' (Colpoma) castanopsidis CA - on chinquapin bark and wood, we have CA ITS, but no local DNA. It appears to belong in the genus Colpoma, as it is within 5% of a sequence purporting to be the type species of that genus.

'Coccomyces' heterophyllae BC - on hemlock twigs, no ITS DNA available

'Coccomyces' cf ledi EU - on Labrador-tea twigs, no ITS DNA available

'Coccomyces' cf leptideus EU - on bilberry, lingonberry, Rhododendron and salal twigs. We have one Chinese sequence that purports to be this.

'Coccomyces' parvulus WA - on conifer wood without bark. No DNA available.

'Coccomyces' pseudotsugae BC - on bark of Douglas fir and grand fir. No DNA available.

'Coccomyces' cf tumidus EU - on hardwood tree and shrub leaves. No ITS DNA available.

Phialina

Phialina cf lachnobrachya EU - tiny, bright yellow stemless cups with white eyelashes growing on leaves. No DNA from anywhere so I cannot even confirm that this is in the proper genus.

Discocainia, Triblidium, etc.

Discocainia treleasei AK - erumpent black spots on conifer wood. This is the type species of the genus, but no DNA is available to place this genus, although I have DNA purporting to be another species in this genus

Triblidium calciforme EU - erumpent spherical cups on oak. This is the type species of the genus, and we have a sequence purporting to be this species, perhaps from China, but no type area DNA and no local DNA.

Rhytismataceae PNW01 - erumpent black cups with a white rim on conifer wood. One OR sequence is near some sequences labeled Colpoma and Lophodermium, but the genus is not known.

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