Three Similar Toadshades in SE USA

Trillium decipiens, T. reliquum , and T. underwoodii form a group of three closely related species. Here are my notes for distinguishing them from one another, taken from the monograph where the other two were first segregated from a broader concept of T. underwoodii.

T. decipiens T. underwoodii T. reliquum
stalk (scape)
carriage
erect erect decumbent*
stalk : leaf
length ratio
2.5 - 3.0
tall-appearing,
leaf tips don't touch ground
1.0 - 2.5
short-appearing,
leaf tips often touch ground
1.6 - 2.0
short-appearing,
leaf surfaces at or near ground level
sepal
carriage at flowering
divergent-spreading horizontal,
or curving back down to touch leaves
variable
length : width ratio 3.0 - 3.5 3.5 - 4.0 3.5 - 4.0
petal
shape
broadly oblanceolate - obovate narrowly oblanceolate to narrowly elliptic usually narrowly elliptic,
but variable
length : width ratio 2 - 3 3.5 - 5 3.5 - 4
occasionally broader
color highly variable, from
green to yellow-purple to brown-purple
brown-purple
(rarely yellowish)
brown-purple
bronze
(rarely yellowish)
anther sac dehiscence lateral lateral introrse
stamen : carpel
height ratio
≈ 1.5 ≈ 1.5 ≥ 2
leaf shape lanceolate
(straight line from widest point to apex)
lanceolate
(straight line from widest point to apex)
broadly elliptic
(convex curve from widest point to apex)

*not nearly as decumbent as Trillium decumbens. In the T. reliquum population I visited, the stalk (scape) will sometimes only hint at 'laxness' with a slight 'S' bend, but at least some plants in a given population should have scapes that grow initially along the ground.

Publicado por ddennism ddennism, 16 de marzo de 2018

Observaciones

Fotos / Sonidos

Square

Observ.

ddennism

Fecha

Marzo 11, 2018 02:17 PM HST

Descripción

50-200 individuals
Edgefield County location #2
possibly a new record?
At a site in danger of immediate development (!!)

Etiquetas

Fotos / Sonidos

Observ.

ddennism

Fecha

Marzo 11, 2018 11:54 AM HST

Descripción

Many individuals
(known population)
Aiken County

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