Alfalfa

Medicago sativa

Summary 6

Alfalfa /ælˈfælfə/, Medicago sativa, also called lucerne, is a perennial flowering plant in the pea family Fabaceae cultivated as an important forage crop in many countries around the world. The English name alfalfa is widely used, particularly in North America and Australia. But in the UK, South Africa and New Zealand, the more commonly used name is lucerne. It superficially resembles clover, with clusters of small purple flowers followed by fruits spiralled in 2 to 3...

Description 7

This introduced perennial plant is 1–2½' tall. A mature plant will tiller from the base, sending up multiple stems that are ascending or erect and branch occasionally. The stems are usually hairless, particularly as they become older. The alternate compound leaves are olive-green and trifoliate. Each leaflet is oblanceolate or obovate, wedged-shaped at the base and nearly truncate at its outer edge. The margin is smooth, except for some dentate teeth along the outer edge. A typical leaflet is about 1" long and 1/3" across, being wider toward its outer edge than at the base. At the base of each compound leaf, are two small stipules that are lanceolate.  Some of the stems terminate in short racemes of flowers. The racemes are about ½–2" in length. Each flower is about 1/3" long, consisting of 5 petals that are lavender or purple, 10 stamens, a single pistil, and a green calyx. It has a typical pea-like structure, with a large standard, a keel, and 2 small side petals. However, the standard and keel are somewhat spread apart, exposing the throat of the flower. The calyx has 5 long teeth, and it often has scattered white hairs. The blooming period usually occurs during the summer, and lasts about 1-2 months. However, some plants may bloom during the late spring or early fall. The flowers are replaced by tightly coiled seedpods that are about 1/3" in length from one end to another (they would be longer if uncoiled). They are flat-sided and have a reticulated surface, sometimes with stiff hairs along the outer edges. Each seedpod contains several seeds that are yellowish brown and reniform. The root system consists of a stout taproot in mature plants. This plant spreads by reseeding itself.

Sources and Credits

  1. (c) Matt Lavin, some rights reserved (CC BY-SA), http://www.flickr.com/photos/35478170@N08/5183007138
  2. (c) 2010 Barry Breckling, some rights reserved (CC BY-NC-SA), http://calphotos.berkeley.edu/cgi/img_query?seq_num=328303&one=T
  3. (c) 2010 Barry Breckling, some rights reserved (CC BY-NC-SA), http://calphotos.berkeley.edu/cgi/img_query?seq_num=334117&one=T
  4. (c) Valter Jacinto, some rights reserved (CC BY-NC-SA), https://s.yimg.com/pw/images/en-us/photo_unavailable_l.png
  5. (c) anonymous, some rights reserved (CC BY-NC), http://www.biopix.com/PhotosMedium/Medicago%20falcata%2000001.JPG
  6. (c) Wikipedia, some rights reserved (CC BY-SA), http://en.wikipedia.org/wiki/Medicago_sativa
  7. (c) John Hilty, some rights reserved (CC BY-NC), http://eol.org/data_objects/29447115

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