Update Notes for V1.2: Guide to the Powdery Mildews of the Americas

First, I'd simply like to thank all active participants! I've gotten feedback from many of you already, while several more have messaged to say that they're now wading into identifying. I appreciate all the enthusiasm as always!

This post is simply a supplement to the updated version of the Guide that I just sent out. I tried to keep the message short and simple as I had to send out a lot of them; consequently I added only a quick note to each person, while the rest of what I would've said (and the tabulation of the more important updates) are all in this post instead. I also have to say, if any of you see this tag but haven't seen my message(s -- either the update or the original), please do check your inbox!

A few people have asked me about when illustrations and/or photos might be added to the Guide. The reality is that I don't know, and soon the field guide writing part of my time will have to be given over to more of my PhD work. I have not made significant further progress on moving toward physical publication of a printed edition of the Guide -- which would certainly have full species accounts and photo illustrations in addition to the keys, but which I won't have enough time to work on during the coming months.

With that constraint, this update might be the last major one for a while. I will add significant changes if necessary, such as if new species are described or new records of species are found in the Americas -- as has already happened! If any of the keys are unusable due to numerical error or excessively ambiguous couplets, that would also merit an update. Otherwise, I will continue to take feedback and corrections but mainly compile them for a later update.

For now, please use the update I've sent out. Let me know any thoughts, comments, questions, and critiques you may have about it -- and keep up the identifying and observing! So far things seem to be going quite well!

On a side note: Greenhouses are an excellent place to look for powdery mildews! They're crowded (lots of plants to infect), humid (perfect for fast growth), usually actively ventilated (blowing the spores all around), and sheltered (no pesky rain or hordes of fungus-eating ladybugs to damage them). I visited some production greenhouses earlier and found incredible amounts of mildew on some of the tree seedlings there -- see attached observations below -- including one or two species I hadn't observed before (Podosphaera pruinosa and Erysiphe cornigena). There are also species described from inside greenhouses, such as the mysterious "Euoidium" pseudolongipes, as well as likely more awaiting discovery, such as a strange pitcher plant powdery mildew I once caught a glimpse of. So if you happen to find yourself in a public or commercial greenhouse, keep an eye out for some familiar pale fungi!

In any case, you can find the important new differences in the Guide V1.2 listed below -- no need to read them all, but for those who are curious, I mostly kept track to share the news.

Happy mildew-hunting!

List of changes in this edition (version 1.2):

Global formatting and content

all couplets are now in the format 1a,1b instead of 1,1' (thanks for the suggestion @epic2112! all testers, kindly let me know if you have any feedback on this!)
species that have relevant notes or "Also look for" relatives at the end of their family's key now are marked with an asterisk * -- this is also mentioned in the front matter (page 10)
additions to 4-criteria section on identifying powdery mildews (thanks @tom1548 for this and the above change!)
glossary entries added and existing ones edited
various typos and minor formatting issues fixed (thanks to all who contributed feedback for each catching some!)

Taxa covered

added Erysiphe pseudolonicerae to Menispermaceae key
added Phyllactinia sapii to Euphorbiaceae key (thanks and congrats to @neontetraploid for both this and the new continent record above!)
added Podosphaera ampla and unknown species on American plums (Prunus sect. Prunocerasus) to Rosaceae key (thanks @epic2112 for finding the latter!)
added Brasiliomyces setosus to Sapindaceae key
added the cotton powdery mildews Phyllactinia gossypina and "Oidiopsis" gossypii to Malvaceae key (along with general Malvaceae key rewrite)
added host family Cercidiphyllaceae and Podosphaera cercidiphylli
added Leveillula lactucarum to Asteraceae key (super last-minute... if you don't have this species in your copy, please check back at the download page!)
added unknown species on Phyla to Verbenaceae key
added Erysiphe guarinonii to main Fabaceae key, replacing its synonym E. baptisiae
added mention of Erysiphe radulescui to Papaveraceae key
added mention to look for Golovinomyces ocimi in Lamiaceae key notes
listed host range of Phyllactinia populi (thanks @leytonjfreid!)
added many genera to those infected by the Golovinomyces ambrosiae complex
listed host range of Erysiphe euonymicola (thanks @epic2112!)
added several genera infected by Erysiphe sedi (thanks @tom1548!)
fully listed host range of Golovinomyces asperifolii
fully listed possible hosts in Myrtaceae

Key usability

rewrote couplets in Rosaceae key pertaining to host plants with thorny canes (thanks @sunguramy!)
rewrote oak couplets in Fagaceae key to accommodate the Erysiphe alphitoides complex
fixed numbering of couplets in Fagaceae key (thanks @david99, @sunguramy, and @epic2112!)
fixed numbering in Asteraceae couplet 6 (thanks @epic2112!)
rewrote Plantaginaceae key for more logical grouping