A note about Trillium grandiflorum (white trillium)

Trillium grandiflorum (white trillium) is putting on a great show this spring. This flower is native to eastern North America (range map here). It is listed as secure in most of its range, but is endangered in Maine and exploitably vulnerable in New York [1], and its status is undetermined in New Brunswick [2]. The species is a member of the family Melanthiaceae.

Trillium grandiflorum

T. grandiflorum is a very distinctive flower, easy to identify. I have already commented quite extensively on this flower in a post I made last summer, including a discussion of its pollinators and its interesting seed dispersal mechanism (myrmechory - ant dispersal).

Trillium grandiflorum population

Where it is not vulnerable to deer predation, T. grandiflorum can form very large, dramatic colonies, like the one pictured above which is in the park portion of the Notre-Dame-des-Neiges cemetery in Montreal (on the west side of the mountain).

Trillium grandiflorum - yes, T. grandiflorum, not T. grandiflorum f. roseum

Sometimes, when people see a trillium like the above, they assume that they are seeing a different variety; there does exist a variety of trillium (T. grandiflorum f. roseum) which is pink. However, this variety is extremely rare, and has a sharper, wavier appearance. This is actually just a regular T. grandiflorum.

Trillium grandiflorum

So if this is a regular T. grandiflorum, why is it pink?

T. grandiflorum is a flower which changes colour as it ages. A pink flower like the above is just an older one, approaching its time of senescence. So when you see a pink individual (or a few pink individuals) among your T. grandiflorum population, just remember that it is more than likely just another T. grandiflorum that happens to be a bit older than the others.

Trilliums - Trillium spp. - Trilles

Trillium erectum (red trillium, fr: trille rouge) and Trillium grandiflorum (white trillium, fr: trille blanc) are common sights in Quebec and Ontario in the early spring. The Trillium genus is in the Lilaceae family based on genetic evidence, though it used to be listed in a separate family and in spite of the fact that it displays a few characteristics which are slightly odd for the Lilaceae family (eg distinct sepals).

All Trillium spp. are myrmecochorous (see yesterday's post for discussion of myrmecochory), spring ephemeral, herbaceous perennials with thick rhizomes, and also display the distinctive sets of three in their morphology which make the trilliums so recognizable. There is a popular theory that Trillium spp. seeds have been dispersed wide distances (post-glacial expansion) by deer herbivory; I would comment only that deer herbivory and myrmecochory shouldn't generally go hand-in-hand as dispersal mechanisms, as myrmecochory is metabolically expensive and we would expect an advantage to the loss of this dispersal system if an alternative were available to the plant.

T. grandiflorum is the provincial flower of Ontario. It is primarily bee-pollinated and its seeds ant-dispersed.

T. grandiflorum in Gatineau Park

In Quebec at least, T. grandiflorum appears to form these vast colonies of thousands upon thousands of individuals. This photo shows a carpet of the flowers extending as far as one can see. In spite of a certain amount of concern over habitat losses and commercial collection for gardening, this species is listed as secure in Canada. Note, however, that it is listed as endangered or vulnerable in the US.

T. grandiflorum - with distinctive sets of 3 (leaves, sepals, petals)

T. grandiflorum flower

T. erectum, unlike T. grandiflorum, is not bee-pollinated. Instead, it is fly-pollinated. This is why it has a distinctly unpleasant odour (usually likened to wet dog); this odour attracts the flies which pollinate the species.

T. erectum flower with distinctive sets of 3

T. erectum is listed as secure in Canada, but, like T. grandiflorum, is listed as endangered, vulnerable, or threatened in the US.

T. erectum flower

I've always had a particular fondness for the red trillium, which is the only one of these two which grows at the lake (the property doesn't have any suitable places for T. grandiflorum)

T. erectum