Margaret Krichbaum

Joined: Jun 01, 2020 Last Active: Oct 22, 2021 iNaturalist.ca

I work as a field botanist in western Canada doing rare plant surveys. Our company is called Eagle Cap Consulting Ltd (named after our original location near the Eagle Cap Wilderness in Oregon). https://www.eaglecap.ca/

My current side projects include field studies in Alberta and British Columbia of:
Artemisia longifolila vs Artemisia herriotii - a complicated subject...
Isoetes howellii
Muhlenbergia andina
Piptatheropsis canadensis
Platanthera aquilonis s.l. (spurless morph), collection and range mapping for planned genetic study by UBC researchers
Potentilla pulcherrima - see below for details, it's complicated!

My husband and I had the recent good fortune to be co-authors on a paper on Isoetes howellii and I. bolanderi with Daniel Brunton and Paul Sokoloff: https://www.canadianfieldnaturalist.ca/index.php/cfn/article/view/2509


More detail on my Potentilla pulcherrima observations:

The problem: we have what appears to be a fairly common plant listed as an S1 Track species in Alberta. I think this may have happened because P. pulcherrima is underreported and undercollected, and maybe that’s due to the confusing way it’s presented in the keys. In Flora of Alberta 2nd Ed. it’s buried at the end in a long list of P. gracilis varieties, and the Flora of North America (FNA) key and description appears to be oriented towards U.S. material with those mysterious red-tipped glands (would love to see that!).

So I’ve set about to collect (by permit where required) and report P. pulcherrima in Alberta (AB) and British Columbia (BC). To do that, I first had to set up a definition of what is and what is not P. pulcherrima, since clearly there’s lots of intergradation going on between various Potentilla species in western Canada. Here’s what I came up with, after studying the FNA key, comparing it to what I was finding, and then running all that past the FNA Potentilla author, who kindly took the time to clarify a few sticking points for me.

Definition of P. pulcherrima for this project (italicized characters are the most important):
-lower leaf surface covered with abundant to dense white cottony hairs (white-tomentose); long hairs are also common;
-upper leaf surface green, not glaucous, with sparse to common long hairs and no cottony hairs;
-leaflets 5-7, evenly incised 1/4-1/2 to midvein with 6-12 broadly lanceolate teeth per side, distal edge of teeth max. 5 mm;
-strictly palmate leaves (slightly subpalmate leaves allowed, i.e., leaflets that are attached on less than the last 1/10 of the leaf axis count as "palmate");
-undivided medial blade fits into the 6-15 mm wide range, usually about 10-14 mm;
-glands are not expected to be reliably present: for my collections, at best, at 31X, I can see a few colorless glands right at the junction of the leaflets and the petiole on both sides of the leaf, underneath the dense long hairs, and that's it; therefore, no “conspicuous, red-tipped glands” are necessary for a positive ID of P. pulcherrima;
-styles 2 mm long, but at this point I’m including also some plants with styles a bit longer (for example, to 2.3 mm when the maximum given for P. pulcherrima is 2 mm);
-epicalyx bractlets 2 mm wide, but at this point I’m including also some plants with bracelets a bit wider (for example, to 2.6 mm when the maximum is given for P. pulcherrima is 2 mm);
-range is east of the crest of the Rocky Mountains in Canada; my personal focus because of where I live and work is in BC and AB, but it would be interesting to collect farther east in Canada as well.

Essentially for field ID this means plants with shallowly-incised, strongly bicolored leaves.

What doesn’t count:
-Plants with only a thin covering of cottony hairs on the underside of the leaflets get separated out as P. gracilis var. fastigiata, FNA’s “catch-all category” (see note in the Discussion section under P. gracilis var. fastigiata in FNA);
-Likewise, plants with leaflets > 7, leaflet teeth relatively long and linear (distal edge of tooth > 5 mm), or undivided medial blade >15 mm are also separated out as P. gracilis var. fastigiata;
-Plants with undivided medial blade <6 mm are P. gracilis var. flabelliformis (these are easy to separate since they have really long leaflet teeth and leaves are basically green on both sides);
-Intergrades with P. hippiana will have bicolored leaves that are not strictly palmate and these are also separated out.

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