Monthly Archives: May 2019

Twinleaf: A Local Spring Wildflower

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Jeffersonia diphylla
Twinleaf

Twinleaf (Jeffersonia diphylla) grows in rich deciduous woods and floodplains. Its distribution is local, meaning it does not grow in every suitable habitat but where it grows it can occur in large numbers. In Michigan it ranges northward to a line passing through Saginaw.

Jeffersonia dubia
Asian Twinleaf

William Bartram named the genus in honor of Thomas Jefferson. One other species occurs in the genus, Asian Twinleaf (J. dubia), growing in eastern Asia. Several other genera occur in Eastern North America and then skip to eastern Asia including: Ginseng (Panax), Lopseed (Phryma), Mayapple (Podophyllum), Lizard’s-tail (Saururus), and Skunk-cabbage (Symplocarpus).

Jeffersonia diphylla
Twinleaf

Twinleaf is an appropriate common name because the two leaf lobes form practically identical segments. Flowering in southern Michigan happens in April. The multi-parted, white flowers resemble Bloodroot (Sanguinaria canadensis) but the two species are not closely related.

Jeffersonia
Native Twinleaf L Asian Twinleaf R

The seeds are myrmecochorous which means distributed by ants. A sweet, fatty blob, called an elaiosome, adheres to the seeds attracting the ants. Ants gather the seeds, take them into their nests, and later eat the elaiosome. Conventional “wisdom” states that the ants gain food and plant’s seeds are moved to a protected and nutritionally richer site for growth. Charles Kwit at the University of Tennessee Knoxville is studying this. One of his students, Mariah Patton, has provided a summary citing research that questions both the benefits to ants and the advantages to the plant. Further research is called for.

 
Copyright 2019 by Donald Drife

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A Color Variant in Yellow Trout Lily (Erythronium americanum)

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Yellow Trout Lily with reddish-brown at base of tepals

Recently I was shown a small patch of Yellow Trout Lily (Erythronium americanum) with the base of the tepals reddish-brown on the inner surface. The two-toned plants are striking. Trout Lilies can reproduce vegetatively through stolons. See my blog from 2017. This patch might be a single clone spreading via stolons.

Erythronium americanum forma castaneum

I checked the Michigan Flora Website and it said, “Rarely the perianth is reddish brown basally. Flora of North America says “Flowers: tepals yellow, sometimes tinged light to dark purple-red abaxially, sometimes with reddish dots adaxially,” So this variation is known. I just never saw it before.

Lyman Smith named this color form as forma castaneum. The condition of the colony he found agrees with my colony except his had smaller flowers. He writes, “I found a large patch of Erythronium americanum much of which was the typical plant. However, many of the plants had flowers rather smaller than the average and with the inner part of the perianth a deep chestnut-brown” (Rhodora, Vol.31, page 36, February 1929). Forma castaneum is used in the Flora of North America to designate the reddish anther form with no mention of flower color. Perhaps this form as named also had reddish anthers and the name was used instead of creating another name for a minor form. 

I addressed the anther color variations in another blog post.

All of our two-toned Yellow Trout Lilies had reddish anthers.  Emily Austen, a postdoctoral fellow in biology at the University of Ottawa is studying the color variations and her blog provides additional information.

My patch was found in Royal Oak, Oakland County, Michigan. It will be interesting to hear of other colonies and their anther color. My thanks to Mushroom Mary for pointing this patch out.

  • Glossary
  • Abaxially means on the front side.
  • Adaxially means on the back side.
  • Tepels are colored sepals. Sepals are the bud coverings with the petals found inside. Trout Lilies lack petals; the yellow flowers parts are tepals.
  • Perianth is the outer part of a flower, made up of the calyx (sepals) and corolla (petals).

 
Copyright 2019 by Donald Drife

Webpage Michigan Nature Guy
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