Superficial resemblance to : Goat's-Rue which is also shrubby, but taller, and with pinnate leaves rather than trefoil leaves and the flowers of Goat's-Rue are in a loose spire and usually lilac or white whilst those of Lucerne have purplish flowers with spiral pods.
Uniquely identifiable characteristics : The helter-skelter like spiral-wound flattened seed pods which have between 2 and 3 complete turns but are without numerous spiny projections.
Distinguishing Feature :
In its cultivated form, Lucerne is better known as Alfalfa, Medicago Sativa. Once widely grown as fodder for browsing animals (but now much less so) it has a very high protein content, about 27%. Because of widespread arable-land planting, it is to still to be found growing on field boundary, road verges, rough grassland and other waste places.
There are three sub-species of Medicago sativa:
Lucerne (Medicago sativa ssp. sative) which is by far the most common. Fruits slightly curved to spiral with 2 - 3 turns. Flowers mauve to violet. 10-20 seeds. Introduced and naturalised.
- Sand Lucerne (Medicago sativa nothossp. varia) which is rather rare RR. Fruits curved or spiralled with 0.5 - 1.5 turns. Flowers yellow or white, or purple or green or blackish. 3-8 seeds. The hybrid between Lucerne and Sickle Medick, but back-crosses and is partly fertile.
Sickle Medick (Medicago sativa ssp. falcata) which is also rather rare RR. Fruits nearly straight to a semi-circle. Flowers yellow. 2-5 seeds. Native in East Anglia, introduced and naturalised elsewhere.
Coumestrol is one of the
coumarins (the two fused 6-membered rings on the right) with a
BenzoFuran moiety (the fused 5 and 6-membered ring on the left) fused onto the other end of it. (Coumestrol should not be confused with Cholesterol (which is a steroidal compound). However Coumestrol does possess
oestrogenic properties, as do all its related compounds, the
Coumestans). Coumestans are oxidation products of
PteroCarpans (which lacks the =O moiety of coumestan) and which are also found in many plants.
Coumestrol is found in many plants from the Brassicacaea family, such as
Pinto Beans and
Lima Beans but the greatest concentrations are found in
Lucerne (aka Alfalfa) and especially so in
Clovers (such as
Red Clover, which makes about 800 times more
Coumestrol than does Lucerne). It is a phyto-oeastragen, mimicking the effects of
oestradiol) within the body, but yet exhibiting anti-oestrogenic properties. It seems that higher levels of Coumestan are found in plants which have suffered attack from aphids, so it may also be a defence chemical against aphids (either that or aphids like coumestrol and the plant willingly obliges with more, although that seems an unlikely scenario). Because Coumestrol is an oestrogen mimic, it is also an endocrine disruptor, meaning it has the potential to disrupt all organ systems hormonally governed by oestrogens and even affecting males, who despite producing normal levels of the male hormone testosterone, are less likely to ejaculate (but this has only been established in rats). But it also affects female rats (in various other ways). Clover in cattle fields adversely affects the reproduction mechanisms of both Cows and Bulls if they consume a lot of Clover.
Coumestrol also exhibits mutagenic properties.