Twinleaf–a President’s Wildflower

Twinleaf in bloom

Twinleaf is a wildflower that blooms in early spring and is native to many parts of eastern North America. It’s found in rich, moist woods, usually in limy soils. It often grows near bloodroot (Sanguinaria canadensis), which has similar looking flowers.

 

Thomas Jefferson’s wildflower

Twinleaf’s scientific name, Jeffersonia diphylla, is in honor of Thomas Jefferson. Twinleaf was first recognized as a separate species in 1792 by physician, botanist, and naturalist, Benjamin Smith Barton (1766 to 1815). Barton named the plant in honor of his friend, Jefferson, who was then Secretary of State under President George Washington. Jefferson himself was an avid naturalist and was friends with many scientists.

Twinleaf gets its common name (and its species epithet, diphylla) from its two-part leaves that grow from the base of the plant.

Twinleaf flower when it first opens

Twinleaf flower loaded with pollen

Twinleaf flowering and pollination

The flowers of twinleaf are about 1” to 1 1/2” wide and have pure white petals, usually numbering eight. The flowers first open in late morning on a sunny, early spring day. Each flower has male parts (stamens and anthers) and female parts (pistils and stigmas). When the flowers first open, the pollen is contained within the anthers. Within hours, the anthers split open and shed their pollen.

The flowers attract few insects, usually only an occasional small bee or fly. If an insect does visit the flowers, it may succeed in transferring pollen from one flower to another and result in cross-fertilization. If not, the flowers can self-pollinate. Self pollination occurs when the flowers close up in the late afternoon, allowing the pollen to come in contact with the stigma. The flowers of twinleaf are frail and short-lived, and the petals will drop quickly if the weather turns windy or rainy.

Twinleaf flowers starting to lose petals

Twinleaf seed pods ready to flip their lids

Large seeds attract ants

Twinleaf fruits and seeds

About eight weeks after flowering, the fruits and seeds of twinleaf mature. The seed pods are unique structures that have what look like lids that pop open to reveal the seeds inside. The seeds are fairly large (about 1/4” to 1/2” long) and shiny, and they have fatty appendages called elaiosomes. The elaiosomes attract ants that carry the seeds back to their nests. There, the ants remove the elaiosomes to feed to their larvae and discard the unharmed seeds in a waste area of the nest. This usually provides ideal conditions for the seeds to germinate the following spring. Rodents often eat the seeds that ants don’t get first.

Twinleaf “planted” by ants

Flowers of bloodroot look similar to twinleaf …

Similarity to bloodroot

… but leaves are different

Twinleaf blooms at about the same time as bloodroot, and the flowers of both plants look similar. But the leaves of each plant are distinctive and are the main clues to identification.

Twinleaf is uncommon to rare

Twinleaf is surprisingly uncommon to rare in its native range. It’s listed as endangered in New Jersey and Georgia and as threatened in New York and Iowa. Even over 100 years ago, in 1906, the Bulletin of the Wisconsin Natural History Society reported of twinleaf, “… it is gradually disappearing from the immediate surroundings of Milwaukee.”

I find twinleaf’s rarity surprising because it does quite well in my native plant garden with average soil and no help from me. Every year, new seedlings pop up all over my yard, likely from seeds collected by ants. And, the deer don’t browse it. I guess I’m fortunate to have such a robust population of these plants.

Jefferson wasn’t the only president honored in a species name

In doing the research for this blog post, I wondered if any other president or high-ranking government official had been honored by having a species named after him or her. The answer is yes … and recently. In 2005, two former Cornell University entomologists, Quentin Wheeler and Kelly Miller, were charged with the task of naming 65 newly discovered species of slime mold beetles. They decided to name three of the slime mold beetles in honor of prominent political leaders of the time. We now have Agathidium bushi, named for President George W. Bush; Agathidium cheneyi, named for Vice President Dick Cheney; and Agathidium rumsfeldi, named for Secretary of Defense Donald Rumsfeld. You can read more about these slime mold beetles here.  And, in 2009, a species of lichen, Caloplaca obamae, was named for President Obama.

Native range of twinleaf from USDA PLANTS Database

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