I’m still on vacation, so my colleague Eric La Fountaine has kindly written today’s entry. He writes:
This species is an herbaceous perennial, with erect, hollow stems reaching 60-80 cm in height. Erect conical racemes of pink flowers arise on these long stalks. The natural distribution of this legume is reported by some authorities to be southern Europe and by others as central or western Asia, but a long history of cultivation as a temperate forage crop makes its native origin a bit muddy. Like many plants with a long period of human use, it is known by many common names. In English, it is commonly called sainfoin from the French for “healthy hay”. Sometimes it is called holy hay–a confusion of “saint” for “sain”.
Healthy hay is a fitting moniker. It is nutritionally comparable to alfalfa and equally, if not more, palatable to livestock. In addition, research has shown that it inhibits nematode parasitism in ruminants due to its high tannin content. A good report on the use of sainfoin as a feed crop is available on Feedipedia: Onobrychis viciifolia, while images of the species growing as a field crop are available via the Alberta Native Plant Council. As a crop, the plant is considered a good environmental choice: it forms a deep tap root that helps soil stabilization, its roots house nitrogen-fixing bacteria that improve the soil, and its melliferous flowers attract bees and birds. A fine, clear honey has been produced in areas where the plant is cultivated. Lastly, it is more tolerant of drought and cold than other forage crops like alfalfa and clover.
Despite its many benefits, it has largely been replaced by alfalfa and clover in the past century. The main drawback is its poor regrowth after cutting and resultant lower production.