The seeds are very curious monsters; I fancy of some plant allied to Medicago, but I will show them to Dr. Hooker.
"The Life and Letters of Charles Darwin, Volume II (of II)" by Charles Darwin
Medicago sp., ?., Europe.
"Vegetable Teratology" by Maxwell T. Masters
Medicago sativa L. Pulse family.
"Texas Honey Plants" by C. E. Sanborn