the Fragrant Orchid are reproduced on the front cover. Another local plant that has
turned up in quantity on the old silt lagoons is Toothed Medick, Medicago polymorpha.
This can be mistaken for a form of Spotted Medick, Medicago arabica without spots
on the leaves, but its fruits are distinctive with a reticulate pattern on the side faces, best
seen on the same side as the stalk (see Fig. 1). Its name is derived from the stipules
which have long laciniate teeth, not to be confused with those of M. arabica which also
have teeth, but these are shortly triangular.
Fig. 1. The fruits of Toothed Medick, Medicago polymorpha
showing the reticulate pattern on the flat faces. Photo Ken Adams.
front face stalk face
a pair of fruits attached to stalks
While on the subject of Orchids, note in the enlargement of Ray's Fragrant Orchid photo
the long, slim, downward curving spur at the back of the flower. Compare this with the
photos of the two extremes of pigmentation in the Common Spotted Orchid
Dactylorhiza fuchsii taken by Matthew Minter at Grays Chalk Pit (plates 7 & 8) where
the spur is short and conical. The all-white flowers are of a mutant unable to manufacture
the pink-red-purple anthocyanin pigments and those with the all-purple lower lip, a
mutant in which the gene(s) that normally controls the distribution of anthocyanin pigment
into discrete lines and spots has somehow malfunctioned. Mutants with these two extreme
phenotypes appear independently and spontaneously quite widely in the U.K. and are a
frequent source of confusion.
Essex Field Club Newsletter No. 57, September 2008 9