Identifying and Differentiating Impatiens capensis and Impatiens pallida

In looking at field specimens, and reading monographs and identification books and sites, there are a number of characteristics that are suggestive of Impatiens capensis vs I. pallida. There does appear to be one characteristic that (at least based on everything I've observed thus far) may differentiate the two definitively, which is the observation by Justin Thomas from the Institute of Botanical Training, stating that:

On LARGER leaves of I. capensis, there are fewer teeth, typically no more than 9
On LARGER leaves of I. pallida, there are more teeth, typically over 9 up to 14.

I have put together a comparison table, along with the references I used, and stored it here: https://1drv.ms/u/s!AlrG7LkZ19f5kbcg_FDbsKuyp8N7dw?e=mxbCCq

My own observations are mostly from southern Michigan, and I welcome comments, additional characteristics, and especially if there are populations that don't follow the tooth number pattern.

Posted on August 10, 2019 03:25 AM by kitkestrel kitkestrel

Comments

Would you please send me a copy of the table, to the e-mail address at the CarexWorkingGroup.com website? I'd like to get this information, but can't seem to use the onedrive website.

-- Barbara (sedgequeen)

Posted by sedgequeen over 4 years ago

Thanks for posting! I just found your forum post from last year. I have an example without flowers sadly that has 18 or so teeth... kind of mind boggling. Do you think this trait is reliable enough to ID the plant to pallida even if you don't have flowers to back it up?
https://www.inaturalist.org/observations/49514998

Posted by aphili8 over 3 years ago

It's not the TOTAL number of teeth, it's the number of teeth PER SIDE.

Posted by causasui over 2 years ago

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