@cdh asked me for more info on Yellow Waterlilies (Nuphar) in Manitoba - so I am reworking my answer to that specific question into this journal post in the hope that it is useful to someone else as well.

At the current state of knowledge we have only two species of Nuphar found here.

• N. variegata (https://data.canadensys.net/vascan/taxon/6715) - with just over 50 Manitoba RG observations
• N. microphylla (https://data.canadensys.net/vascan/taxon/6713) - for which we do not have an RG observation on INat in Manitoba yet....there are 12 RG observations in Canada

The leaves of N. microphylla do not get larger than 10 cm long while N. variegata leaves are generally 7-35 cm in length; flower size has a similar pattern - N. microphylla 1-5 cm and N. variegata 5-11 cm. This size difference is the main characteristic I have been using for my ids to date.

Other things to look for are:

• N. microphylla has a red disk with 6-10 rays, globose fruit with no decaying stamens at its base, a narrow v shaped sinus on the leaf;
• N. variegata has a green or yellow disk with 7-25 rays, fruit is constricted above with decaying stamens at its base when young and a closed or narrow sinus on the leaf.

My source for all these details is Scoggan's Flora of Manitoba - still usable after all these years once I figure out the changes in the names.

As to why only N. variegata as opposed to N. lutea and all the rest- my suspicion is that N. variegata has better adaptation to the long cold winter :) Scoggan describes N. microphyllum as occurring in the southern half of the province with the northernmost collection at Cranberry Portage and N. variegatum occurring in the southern four-fifths of the province with the northernmost collection at Reindeer Lake

Have fun looking for them both!

Posted on August 6, 2021 03:02 PM by marykrieger