Cottongrasses in New England

The cottongrasses are a genus of flowering plants in the sedge family. There are six species of cottongrasses in New England, five of which are known to occur in all New England states. For more info about the cottongrasses in New England, see the following document:

The linked document contains identification tips, short descriptions, habitats, flowering phenology, and observation links for each of the species.

Posted on 04 July, 2024 19:23 by trscavo trscavo

Comments

Wonderful work...thanks for this!

Posted by hollyyoung 3 months ago

Excellent resource. Thank you for compiling this!

Posted by tsn 3 months ago

I updated the googledoc with respect to the season of Tussock Cottongrass (Eriophorum vaginatum). Yesterday I was at the Morristown Bog and found that species at the very end of its season, with a few tufts of seeds clinging to stems here and there. (In contrast, Eriophorum virginicum was budding and flowering at its side.) Apparently Eriophorum vaginatum leads a double-life in New England…at the higher elevations, the season is shifted by two or three weeks.

Posted by trscavo 3 months ago

Yesterday I found three species of Eriophorum (or so I claim) at Valcour Bog in Morristown. Not surprisingly, Eriophorum virginicum was budding and flowering throughout. The other two species have been tentatively identified as Eriophorum gracile and Eriophorum tenellum. Based on the keys in New Flora of Vermont (2015) and Flora Novae Angliae (2011), and my review of the (relatively few) observations in New England, there doesn't seem to be much (morphological) separation between the two species. My IDs were based on the length of the uppermost leaf blade (relative to its sheath) but I suspect that character alone may not be enough to distinguish the two.

To straighten this out, I need to go back to this place and take another look. I don't want to go back alone, however, since the quaking bog mat is some cause for concern. Yesterday I was concentrating more on my next step than on the field work at-hand.

Posted by trscavo 3 months ago

At last count, there were eighteen observations of Eriophorum virginicum stuck at subfamily. Actually, one of those observations is not Eriophorum virginicum (since it doesn't have multiple long bracts) but I don't know how to exclude it from the previous list.

Posted by trscavo 3 months ago

I just made a pass over a subset of observations of Rhynchospora alba observed in June and July, and sure enough, there were numerous observations of Eriophorum virginicum lurking in there. So now there are dozens of observations of Eriophorum virginicum stuck at subfamily.

cc: @tsn @michael_oldham @bickel

Posted by trscavo 3 months ago

Fewer now.

Posted by tsn 3 months ago

Thanks Tom! The flowering phenology charts for this species are getting much better.

Posted by trscavo 3 months ago

I went through the observations of Eriophorum virginicum stuck at subfamily and agree that all are E. virginicum. Nice to clean these up ... seems to be a common mistake!

Posted by michael_oldham 3 months ago

Thanks Michael!

Posted by trscavo 3 months ago

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