Jeffersonia diphylla (L.) Pers. (Twinleaf)

Jeffersonia diphylla (Twinleaf) flowers, April 15, 2015.

The genus Jeffersonia was named by Benjamin Barton in honor of Thomas Jefferson, third president of the United States.  There are only two species in the genus, including Jeffersonia diphylla (Twinleaf), native to northeastern United States. The other representative, J. dubia, is from eastern Asia. Twinleaf is found in rich mesic forests in many eastern states, often on slopes and usually over limestone or other calcareous rock.  It is uncommon to occasionally encountered in most states, considered rare in nine (Minnesota, Iowa, Wisconsin, Michigan, New York, New Jersey, North Carolina, Georgia, and Alabama) of the seventeen states it is found, and is protected as a state-listed species in four states (Georgia, Iowa, New York, and New Jersey).  In Illinois, twinleaf is uncommon, but not currently considered rare or protected.

Close up of Jeffersonia diphylla (Twinleaf) flower with eight white petals and eight stamens.

Jeffersonia diphylla (Twinleaf) fruit capsule showing the incomplete dehiscence, resulting in a frog-mouth appearrance.

 

Jeffersonia diphylla (Twinleaf), April 15, 2015.

The showy white flowers appear in early spring (early to mid-April) and are present for a very short time, being blown off by the slightest breeze.  They rarely last more than a single day.  The flowers appear to be pollinated by small halictid bees; however, they exhibit an apparent self-pollinating mechanism that ensures seed production without insect visitation.  Two to three days after flower initiation, often with the showy petals already lost, the eight stamens all bend inward to contact the stigma.  The resulting fruit matures in early to mid-June.  The fruit is an interesting pear-shaped capsule that when fully open has the appearance of a frog with a gaping mouth.  After flowering the namesake leaves continue to grow until they somewhat resemble a pair of small elephant ears.

Jeffersonia diphylla (Twinleaf) showing enlarged elephant ear like leaves.

References:

Kartesz, J.T., The Biota of North America Program (BONAP). 2015. North American Plant Atlas. (http://bonap.net/napa). Chapel Hill, N.C. [maps generated from Kartesz, J.T. 2015. Floristic Synthesis of North America, Version 1.0. Biota of North America Program (BONAP). (in press)].

O’Rourke George, L. 1997. Jeffersonia. In: Flora of North America north of Mexico, Volume 3. Oxford University Press, New York, NY

 
Smith, B.H., M.L. Ronsheim, and K.R. Swartz. 1986. Reproductive ecology of Jeffersonia diphylla (Berberidaceae). American Journal of Botany 73(10):1416-1426.