Status: Exotic
Synonyms:
None
Medicago lupulina is ubiquitous on dry ground throughout most of the Gila from
lower elevations up to over 9000 feet. It has ovate trifoliate leaves and globose
pale yellow flower heads. It can also be found in town in cracks in the sidewalk. The fruits are small and coiled into a kidney shape. Eventually the fruits turn black, giving rise to the common name "Black Medick."
Nitrogen-fixing root nodules are present on the smaller roots of M. lupulina. These nodules appear pink due to the presence of
leghemoglobin. The leghemoglobin buffers the oxygen content of the nodule cells. If the oxygen content is too high, the oxygen-sensitive nitrogen-fixing enzyme nitrogenase stops functioning. If the oxygen content is too low, Rhizobium (the nitrogen-fixing bacteria within the root nodule cells) cellular respiration cannot take place.
Please click on an image for a larger file.
Medicago lupulina, photo Russ Kleinman, Pinos Altos Range, signal Peak turnoff, July 2, 200
Medicago lupulina, photo Russ Kleinman, Bill Norris, Kelly Kindscher & Danielle Walkup, Mogollon Mtns., Bursum Road, July 23, 2008
Medicago lupulina, inflorescence, photo Russ Kleinman & Karen Blisard, Pinos Altos Range, Meadow Creek, Oct. 10, 2008
Medicago lupulina, 1x macro of inflorescence, photo Russ Kleinman, Karen & Evelyn Blisard, Silver City, sidewalk in front of Adobe Springs, Jan. 9, 2009
Medicago lupulina, 3x macro of inflorescence, photo Russ Kleinman, Karen & Evelyn Blisard, Silver City, sidewalk in front of Adobe Springs, Jan. 9, 2009
Medicago lupulina, 5x macro of inflorescence, photo Russ Kleinman, Karen & Evelyn Blisard, Silver City, sidewalk in front of Adobe Springs, Jan. 9, 2009
Medicago lupulina, 1x macro of coiled fruits, photo Russ Kleinman, Karen & Evelyn Blisard, Silver City, sidewalk in front of Adobe Springs, Jan. 9, 2009
Medicago lupulina, 2x macro of coiled fruits, photo Russ Kleinman, Karen & Evelyn Blisard, Silver City, sidewalk in front of Adobe Springs, Jan. 9, 2009
Medicago lupulina, photomicrograph of nitrogen-fixing root nodules, photo Russ Kleinman & Karen Blisard, Silver City, WNMU campus, behind Harlan Hall, November 9, 2017
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