Talk:Trillium sessile

Latest comment: 2 years ago by Trscavo in topic Relative stamen length character

Naming issues

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The discrepancy in the Native American Ethnobotany Database documented in the section on "Uses" is likely a result of the naming issue described in the section on "Taxonomy". I haven't read the ethnobotanical paper summarized in the database but I'll wager the actual plant in question is Trillium chloropetalum, which was erroneously called Trillium sessile var. californicum around the time the paper was written. Tom Scavo (talk) 20:56, 20 January 2022 (UTC)Reply

Relative stamen length character

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The article as written really hammers home the idea that the petal length : stamen length ratio must be over 2.0. The claim appears three times in this single encyclopedia article. But the works referred to in the article disagree. Shaver (1959) notes a mean ratio of 1.7; assuming a symmetric distribution, this means well over half the specimens Shavers examined had stamens that were in fact less than half the petal length. Freeman (1975) doesn't emphasize this ratio at all; his key instead places emphasis on the stamen : gynoecium height ratio (which is wise; petals change length during flowering, moreso than the gynoecium) and other characters, like ovary shape and anther connective prolongation length. Likewise, the Case (2006) reference does not outright mention the ratio, even in its key.

In works I have seen where the "about half as long" ratio is claimed, there is always a qualifying "about as" or "approximately", and it is usually in the context of contrasting T. sessile with species where the petal length : stamen length ratio is closer to 3.0, or even higher (e.g. Michigan Flora, Flora of the Southeastern US), that is, cases where the contrast is more obvious.

My concern is that people will misidentify T. sessile plants due to this overemphasis on a single character, and misrepresentation of the ratio itself (it is "centered about 2.0" or "approaching 2", not always over 2 as the article puts it, repeatedly). In fact, it is more often below 2 than above it, if Shaver is to be believed, so the article is inaccurate for the majority of T. sessile plants. Doppelbrau (talk) 21:26, 1 February 2022 (UTC)Reply

I think that's a fair assessment of the issue, and I agree something needs to be done. Tom Scavo (talk) 13:34, 2 February 2022 (UTC)Reply
I propose the following: 1) edit the description ("The stamens are about half as long as the petals"); 2) edit the image caption ("Flower with relatively long stamens"), and 3) rewrite the Identification section (remove the claim that the "stamens are at least half as long as the petals"). In the process of rewriting that section, cite Michigan Flora and FSUS. Tom Scavo (talk) 16:14, 2 February 2022 (UTC)Reply
The specific edits listed above have been made (diff). The content of the Identification section has been reorganized, and citations to Michigan Flora and FSUS have been added (diff). Tom Scavo (talk) 13:31, 3 February 2022 (UTC)Reply
Of Trillium sessile, Fernald (1950) claimed "stamens half as long as petals". Shaver (1959) reiterated this claim: "stamens about half as long as petals" (p.32). Michigan Flora (2011) incorporates the claim into its key: "petals not over 4 cm long, about twice as long as stamens or shorter". More recently, Flora of the Southeastern United States (2020) does likewise: "stamens about 0.5× as long as the petals". These sources provide more than enough justification for including the claim in the article, I think. What's interesting is that Freeman (1975) does not mention this character. He cites Shaver numerous times but curiously omits the latter's treatise on Trillium sessile. It seems as though he did so intentionally.