Status: Exotic
Synonyms:
Medicago minima (L.) L. var. compacta Neyraut
Medicago minima (L.) L. var. longiseta DC.
Medicago minima (L.) L. var. pubescens Webb
Medicago minima is an exotic weed in our area. It has three lobed leaves with obovate leaflets and the stems and leaflets are hairy. The flowers are small and bright yellow. The fruits are the most distinctive character, being spirally wound and armed with what appear to be small fishhooks. Medicago minima is found in city sidewalks and waste areas where their sprawling form traps elms seeds and other wind carried material. Many thanks to Christopher Davis who recognized this plant as M. minima.
There are small nodules on the roots of Medicago minima. Within these delicate nodules are bacteria of the Rhizobium group that trap
nitrogen from the air and convert it into a form that plants can then incorporate into organic molecules. This process is called
Nitrogen fixation.
Please click on an image for a larger file.
Medicago minima, photo Russ Kleinman & Bill Norris, Silver City, June 10, 2010
Medicago minima, closeup of leaf with three obovate pubescent leaflets, photo Russ Kleinman & Bill Norris, Silver City, June 10, 2010
Medicago minima, closeup of flower & fruit, photo Russ Kleinman & Bill Norris, Silver City, June 10, 2010
Medicago minima, plant measured in lab with standard 15cm rule, photo Russ Kleinman & Bill Norris, Silver City, June 10, 2010
Medicago minima, macro of spirally wound and armed fruit, photo Russ Kleinman & Bill Norris, Silver City, June 10, 2010
Medicago minima, photomicrograph of nitrogen fixing root nodule, photo Russ Kleinman, Silver City, November 6, 2017
Medicago minima, photomicrograph of nitrogen fixing root nodule, photo Russ Kleinman, Silver City, November 6, 2017
Medicago minima, photomicrograph of nitrogen fixing root nodule, photo Russ Kleinman, Silver City, November 6, 2017
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