May 20, 2024

Salmon Hole

I recently visited the Salmon Hole in Burlington. Salmon Hole has a remarkably diverse assortment of plant species, including many non-native plant species and numerous invasive species.

Most spectacular invasive species. A massive invasion of lesser celandine (Ficaria verna) blanketed the steep slope from Riverside Avenue down to the Winooski River. This was the first time I had seen this species in Vermont. It was an impressive display.

Most spectacular native species. A mature population of red trillium (Trillium erectum) was also growing on the slope leading down to the river. Small groups of plants had variously-colored petals (not just typical red). There's a population in the southern Appalachians with pure white petals called Trillium erectum var. album, so the plants at Salmon Hole are technically called Trillium erectum var. erectum (according to the iNat taxonomy). The population here is very old, at least decades old, probably more.

Most surprising observation. I found a sunburst lichen (order Teloschistales) growing on a granite post along Riverside Avenue. There are similar posts used in multiple places along Riverside Ave…it would be interesting to see if this lichen is on other posts. I wonder what granite quarry the posts came from?

Life first. I observed nipplewort (Lapsana communis) for the first time at Salmon Hole. In the field, I had no idea what it was but the leaves had a distinctive shape so the plant's identity was easily guessed (and later confirmed by @tsn).

Posted on May 20, 2024 04:18 PM by trscavo trscavo | 4 observations | 2 comments | Leave a comment

May 15, 2024

Tiarella in New England

A revised taxonomy of Tiarella in eastern North America was proposed in July 2021. (Nesom 2021) The new taxonomy was subsequently accepted by Plants of the World Online (POWO), Flora of the southeastern United States (FSUS), VASCAN, and others. iNaturalist (which follows POWO) split Tiarella cordifolia into five species in November 2022.

In New England, the new taxonomy reduces to a name change, from Tiarella cordifolia to Tiarella stolonifera. New Flora of Vermont (2015) and Flora Novae Angliae (2011) accept Tiarella cordifolia and Tiarella cordifolia var. cordifolia, respectively. As of May 2024, Go Botany (an online version of Flora Novae Angliae) recognizes Tiarella cordifolia var. cordifolia as well.

Prior to the split, the taxonomy of Tiarella in the southeastern U.S. was sorely in need of change, so the new taxonomy was welcomed by some (e.g., FSUS). To others, the name change appears to be arbitrary. Indeed, a significant number of iNaturalist users have pushed back on the change.

At this point, it would be helpful if the authors of New Flora of Vermont and Flora Novae Angliae rendered an opinion on the matter.


Primary source:

Related journal articles:

Posted on May 15, 2024 04:05 PM by trscavo trscavo | 1 comment | Leave a comment

May 14, 2024

Vermont Protected Lands Database

The Vermont Protected Lands Database is a public database of protected lands in Vermont. By definition, a protected land has "some level of protection against permanent conversion to developed land uses". The database includes both public lands (national forests, state parks, town forests, etc.) and privately-owned lands. Many (but not all) of the parcels in the Vermont Protected Lands Database are publicly-accessible lands. A protected land does not necessarily imply public access.

Getting Started

  1. Click "View Map" (dismiss warning: "Too Many Records")
  2. Click the magnifying glass in the top righthand corner
  3. Search: Colchester, VT
  4. Hover over a dark blue parcel to view its name
  5. Click on a dark blue parcel to view its metadata

I use the Vermont Protected Lands Database to discover places to explore. More importantly, I routinely download parcel polygons from the database and build maps prior to field trips. In the field, I access these maps on my smartphone, which of course is GPS-enabled. In this way, I always know where I am.


Posted on May 14, 2024 05:13 PM by trscavo trscavo | 1 comment | Leave a comment

May 09, 2024

Yellow Archangel in New England

The yellow archangel (Lamium galeobdolon) is native to Europe and western Asia but it is widely introduced in Europe, New Zealand, Canada, and the United States, including New England. Lamium galeobdolon consists of four closely-related subspecies:

  1. Lamium galeobdolon subsp. argentatum
  2. Lamium galeobdolon subsp. flavidum
  3. Lamium galeobdolon subsp. galeobdolon
  4. Lamium galeobdolon subsp. montanum

Subspecies argentatum, the variegated yellow archangel, is highly invasive. In the states of Washington and Oregon, it is listed as a Class B Noxious Weed and therefore banned from sale by state law. Subspecies argentatum is present in New England. Other subspecies may also be naturalized in New England.

According to Flora Novae Angliae (2011), Lamium galeobdolon is confined to Maine and Massachusetts in New England. However, as of March 2024, there are hundreds of research-grade iNaturalist observations of Lamium galeobdolon subsp. argentatum spread across all New England states. According to New Flora of Vermont (2015), Lamium galeobdolon is said to be rare in Vermont (apparently based on a single specimen collected in Chittenden County in 2008), but as of March 2024, there are dozens of research-grade iNaturalist observations of Lamium galeobdolon subsp. argentatum scattered across ten counties in Vermont. These data suggest Lamium galeobdolon subsp. argentatum is now widespread (and increasing) throughout Vermont and all of New England. For links to observation pages and summaries of observations counts, see the following document:

For more information, including numerous reliable sources, see the article on Lamium galeobdolon in wikipedia.

Posted on May 09, 2024 02:02 PM by trscavo trscavo | 6 observations | 4 comments | Leave a comment

April 30, 2024

Identification of Trillium ovatum

Trillium ovatum is a white-flowered pedicellate trillium native to western North America. For decades, botanists have recognized two taxa, but based on unpublished data circulated in 2019, Plants of the World Online (and therefore iNaturalist) came to recognize four taxa. An identification key for this group of trilliums appeared in a journal article in March 2024, but since the article is not easily accessible, the key has been reproduced in the following document:

A full citation to the journal article plus links to related resources are included in the linked document.

Posted on April 30, 2024 01:21 PM by trscavo trscavo | 4 comments | Leave a comment

April 04, 2024

Variegated Yellow Archangel

The variegated yellow archangel (Lamium galeobdolon subsp. argentatum) is believed to be native to Europe (but its origins are unknown). It has become an invasive subspecies in several European countries, including the Netherlands, Britain, and Switzerland. It was introduced as a garden plant in New Zealand and North America (and probably elsewhere) where it escaped cultivation and became naturalized. In New Zealand, it is listed by the 2020 National Pest Plant Accord and therefore banned from sale, propagation, and distribution throughout the country. It is also listed by the Invasive Species Council of British Columbia in Canada. In the U.S. states of Washington and Oregon, it is listed as a Class B Noxious Weed and therefore banned from sale by state law.

Botanists in Europe recognize four closely-related taxa, either as subspecies of Lamium galeobdolon or as full species, usually in genus Lamium but also in Galeobdolon or Lamiastrum. Most North American authorities recognize a single taxon, referred to as either Lamium galeobdolon or Lamiastrum galeobdolon. In any case, multiple taxa are not recognized in North America.

The invasive subspecies argentatum is readily distinguished by its silvery white variegated leaves. It is sometimes confused with a cultivar of subspecies flavidum known as 'Hermans Pride', which also has silvery markings on its leaves. Unlike subspecies argentatum, however, subspecies flavidum is not stoloniferous, and therefore 'Hermans Pride' is not invasive.

For more information, including numerous reliable sources, see the article on Lamium galeobdolon in wikipedia.

Posted on April 04, 2024 12:38 PM by trscavo trscavo | 21 comments | Leave a comment

March 21, 2024

Annotation feedback

Recently, a number of GitHub issues related to annotations have been opened and discussed:

I wanted to take this opportunity to provide some feedback to the designers and developers without disrupting the GitHub issues. Hence this journal article.

Background: A group of us initiated and discussed a Proposal to replace the Plant Phenology annotation last November (2023). The proposal was not brought to a wider audience since it was felt that we lacked consensus on one or two key issues. In any case, I think some good points were raised, and apparently now is the time to surface these ideas to the designers and developers.

Briefly, the proposal is to replace the Plant Phenology annotation with the following annotation:

Reproductive Structures
1. Flower bud: At least one closed flower bud is visible
2. Flower: At least one open flower is visible
3. Fruit: At least one fruit or seed is visible
4. No reproductive structures: No sexual reproductive structures (in whole or part) are visible

Instead of modifying the current Plant Phenology annotation, can we modify the proposed Reproductive Structures annotation?

Here are some (out-of-band) comments on the GitHub issues:

#4046: See above for recommended annotation name, values, and mouseover definitions

#4047: The annotation name (Reproductive Structures) should be independent of the chart title. Put another way, user interface issues on the taxon page should not drive the choice of annotation name, values, or mouseover definitions.

#4049: No comment

Posted on March 21, 2024 09:28 PM by trscavo trscavo | 7 comments | Leave a comment

February 25, 2024

The confusing tick-trefoils

Desmodium glabellum (tall tick-trefoil) and Desmodium perplexum (perplexed tick-trefoil) are members of the Desmodium paniculatum complex. The specific name perplexum suggests these taxa are confusing, which is indeed true. Until recently, it was very difficult to distinguish Desmodium glabellum from Desmodium perplexum. In 2020, a breakthrough research result put these species on the map (both figuratively and literally). For more info:

The googledoc includes an identification key, references, and links. A short glossary is also included.

Posted on February 25, 2024 01:30 PM by trscavo trscavo | 14 comments | Leave a comment

February 10, 2024

Bristol Pond

Bristol Pond (also called Winona Lake on some maps) is a large wetland complex in the town of Bristol in Addison County, Vermont. Bristol Pond is the source of Pond Brook, which flows north through the adjacent town of Monkton before emptying into Lewis Creek (which itself empties in Lake Champlain). The Pond Brook Watershed is a significant natural resource (but that's a different story).

There are no hiking trails around Bristol Pond. The best way to experience the area is by canoe or kayak. For convenience, I made a geospatial PDF map of Bristol Pond. The blue area on the map is State land while the yellow area is private land owned by the A. Johnson Company.

I've only been to Bristol Pond once but my sense is that there's a lot to see and do here. You can browse the site's observations to get idea about biodiversity.

Have you been to Bristol Pond?

Posted on February 10, 2024 08:38 PM by trscavo trscavo | 4 comments | Leave a comment

February 04, 2024

A. Johnson Company is closed

As of the end of the December 2023, the A. Johnson (lumber) Company in Bristol, Vermont is closed. There's almost nothing online about this so I won't try to provide a link at this time (see the comments). If today's date were April 1st, I would wonder if this might be an April Fool's joke. If A. Johnson is closed, that's a Very Big Deal since they own many acres of forested land throughout the state.

Does anybody know more?

Posted on February 04, 2024 06:43 PM by trscavo trscavo | 7 comments | Leave a comment