Wild White Indigo ~ Baptisia lactea (B. alba)
Wild white indigo plants grow in open, mesic prairies in full sun.
The flowers of wild white indigo are protandrous - the male reproductive organs develop before the female reproductive organs. Flowers open and mature from the bottom upwards on the raceme.
After bumble bees seek out the higher nectar rewards on the pistillate flowers, they work their way up the flower raceme to the upper flowers in the staminate (male) phase. Pollen is therefore transferred during the last stage of their visit on staminate (male) flowers. The bumble bees move on to a new flower raceme carrying pollen with them to pollinate the next staminate (female) flower visited.
Once the flowers are pollinated, an inflated seed pod develops housing the seeds, turning from light green to dark gray over the summer.
To save energy and resources, wild white indigo plants often abort pods during ripening, especially those with weevil populations inside. The pods decay and the developing weevils inside die.
Haddock, R. C., & Chaplin, S. J. (1982). Pollination and seed production in two phenologically divergent prairie legumes (Baptisia leucophaea and B. leucantha). American Midland Naturalist, 175-186. Retrieved from http://www.jstor.org/stable/2425307
Horn, S., & Hanula, J. L. (2004). Impact of seed predators on the herb Baptisia lanceolata (Fabales: Fabaceae). Florida Entomologist, 87(3), 398-400.
Petersen, C. E., Petersen, R. E., & Meek, R. (2006). Comparison of common factors affecting seed yield in the congeners, Baptisia alba and Baptisia bracteata. Transactions of the Illinois Academy of Science99, 31-36.
Petersen, C. E., & Sleboda, J. A. (1994). Selective pod abortion by Baptisia leucantha (Fabaceae) as affected by a curculionid seed predator, Apion rostrum (Coleoptera). Great Lakes Entomologist,
27, 143-143. Retrieved from http://insects.ummz.lsa.umich.edu/mes/gle-pdfs/vol27no3. pdf#page=18