HORTUS GKAMIJSEUS WOBURN ENSIS. 141 



TRIFOLIUM medium. Marl-Clover, Cow-grass. 



Specific character : Spikes loose, stems flexuose, branched ; 

 corollas nearly equal ; stipules sublate, linear. 



Obs. — The common broad-leaved red clover is distin- 

 guished from the present plant by the spike, which is 

 loose and rather oblong, while that of the broad-leaved 

 clover is globular and compact. The root of the marl- 

 grass is creeping, that of the broad-leaved clover spindle- 

 shaped and fibrous. The stem of the perennial sort is 

 more constantly zig-zag. The leaves are also smoother 

 and longer. There are three varieties of the broad- 

 leaved clover (trifolium pratense), mentioned by bota- 

 nical writers, one of which is said to be perennial and 

 the true marl or cow-grass ; but all the seeds and 

 plants I have had for this (except that from Messrs. 

 Gibbs and Co., which proved to be the present plant) 

 have turned out only two-year-lived plants, or never 

 exceeding three, though cultivated on various soils. 

 Since the above details were first printed, I have found 

 the true trifolium j^ratense perenne in the rich grazing 

 lands in the vale of Aylesbury, and also in the rich 

 grazing lands in Lincolnshire — a figure of which is 

 presented to the reader in the following pages. The 

 plants of marl clover upon which the following experi- 

 ments were made, were taken from a rich ancient 

 pasture, which was so closely cropped at the time, that 

 the plant was only three inches high, though in flower. 

 This plant is also frequent on cold tenacious clayey 

 soils, where it is of smaller stature, more woody, and 

 darker coloured ; but when transplanted to a richer 

 soil its appearance is much altered. The distinctions 

 of the perennial and the biennial root are the most 

 certain, and of the most importance to the agriculturist 

 in choosing between two plants of nearly equal value 

 for the purpose of permanent pasture. To avoid any 

 chance of mistake, therefore, I here present a figure of 

 tlie marl clover or cow-grass, which I have brought 



