Margaret Krichbaum

Unido: 01.jun.2020 Última actividad: 02.jul.2022 iNaturalist Canada

Thank you to everyone who is engaging with me on this website, both in terms of reviewing and IDing my observations as well as taking part in discussions and IDs of other people's observations. This is fun and I am learning so much.

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 in BC, and also vs Artemisia tilesii in AB - a complicated subject, see below
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!
Oxytropis campestris var. davisii

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 Artemisia longifolia observations:

The apparent problem: the morphological variation of northern Canadian populations of Artemisia longifolia Nuttall is not well understood and is creating some nomenclatural confusion.

Following an arc from SE Alberta into NE British Columbia, A. longifolia can be seen to progress from its typical small, gray-aspect form found on hard, very dry clay badlands slopes, into a sometimes very large, lush green-aspect form found on either loose, relatively moist, slumping slopes or level cobble bars.
The Illustrated Flora of BC recognized the BC Peace River region plants as A. longifolia (while remaining a bit vague about the variability of forms); the taxon is described as “...rare in NE BC, known only from the Peace River drainage near the AB border; E to SK and S to SD and CO”.

Due to increased botanical work in the BC Peace River region in the past 15 years, the large, lush forms of A. longifolia started to be better documented. The taxon’s remarkable similarly to the old name A. herriotii Rydberg was noted and here is where the confusion arose: the BC Conservation Data Centre decided to recognize the name A. herriotii in place of A. longifolia, I think as a marker for these large, lush plants that appear so different from the typical form. However, the name A. herriotii is currently considered an accepted synonym of A. ludoviciana ssp. ludoviciana by the Flora of North America; for those of us familiar with both taxa and their habitats, it is quite obvious that these are different plants!

So, I decided to try to find out what was going on. My initial assumption was that the BC Peace River region plants were a distinct taxon, and that I would find a clear break somewhere in Alberta where the A. longifolia dropped out and the A. herriotii form took over. I’ve now collected at five representative sites in AB and numerous sites in the BC Peace region. The result is that I cannot see a clear break; instead, the plant form and the habitat gradually shift from SE AB to NE BC. Therefore, my current feeling is that all the plants are A. longifolia, with the change in form going hand-in-hand with the change in available habitats and increased moisture as one moves north and west.

This is very much a work in progress. There are many more sites I’d like to visit in AB, and I have not yet searched all iNaturalist Artemisia observations in order to pinpoint more locations of both of these forms of A. longifolia. So, stay tuned!

Here is what the observations I have so far are trying to show:

-A. longifolia in SE AB is generally found on dry, hard clay slopes and is a relatively smaller plant with a gray aspect, although it is possible to find some plants growing on slumping banks quite near water, and it is possible to find greenish-aspect, somewhat larger plants in these areas (examples: Dinosaur Provincial Park & Little Bow Provincial Park, AB).

-In central AB, one finds plants of both gray and green aspect and of variable size growing together at the same site, still mostly on hard clay soil but with more moisture apparently available (to judge by the surrounding plant communities and nearby bodies of water) (examples: Rolly View, Edmonton, & Dunvegan, AB).

-Key transition sites have both dry, hard clay slopes supporting smaller gray-aspect forms and moist, looser soils supporting larger green-aspect forms (Dunvegan, AB & Clayhurst, BC).

-The remaining sites so far seen by me in NE BC fall into two types:
---Main habitat: quite large patches of hundreds or thousands of plants on open, steep, loose, slumping slopes along the Peace River in particular, but also along other rivers and large streams in the region. Large patches have also been found on similar loose soils at large, open hillside seeps (not far from a stream or river). The A. longifolia plants at these sites are often quite large and lush when well established (examples: Peace River upstream of Kiskatinaw River, Bear Flat, Halfway River).
---Secondary habitat: scattered single plants or small patches of plants on open to shaded, level river shore cobble bars (active or stabilized) or cutbanks. The A. longifolia plants at these sites can be large but are generally mid-sized to small (examples: Peace River at Blackfoot Park, Peace River near the Beatton River).

-Aspect, leaf forms, and array forms vary considerably from SE AB to NE BC, but all plants key to A. longifolia if one allows that the possible lack of northern Canadian material for study by the FNA authors limited their understanding of the maximum plant, leaf, and array sizes.

-Other features such as bicolor leaf faces, leaf margins, occasional large leaf lobes, and size of individual flower heads remain consistent across the range and remain very close to the description of A. longifolia as given in FNA.

-It would probably be simpler if the BCCDC would consider returning to the use of the name A. longifolia for all NE BC plants in order to avoid any confusion with A. ludoviciana var. ludoviciana, a different plant with a different range and habitat preference.

Of note, things are even more confusing in central Alberta, where the name A. tilesii also comes into the mix for these large, lush plants, as seen in these specimens at ALTA:
https://photos.app.goo.gl/PDsWJJ5fXy2oQjtu8


More detail on 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;
EDIT 2022-02-24: found a specimen that has lots of colourless glands! https://inaturalist.ca/observations/97683496
-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 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);
-Intergrades with P. hippiana will have bicolored leaves that are not strictly palmate and these are also separated out.

UPDATE 2022-05-19:
With the help of some local iNat folks over the winter (Thank You!), there is now assembled a nice set of P. pulcherrima observations for AB. Using the Observation Field tool, I've sorted these into Documented: Yes or No, which helps me generate a nice map of all the many P. pulcherrima observations that now need to be visited for verification!

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