DIADELPHIA DECANDRIA. 163 



toothed on the margins. In other respects the plant is 

 not altered, and cannot deceive the student under this 

 disguise, however it may interest him. 



* * * Flowers capitate. Seeds single. 



3. T. pratense^ spikes dense ; stems ascending ; petals unequal ; 

 calyx hairy, 4 of its teeth equal ; stipulas ovate, bristle, pointed- 

 Common Purple Clover. 



Hab. Meadows and pastures. May Sept. 11 



The " Cow-grass'* of farmers, who seem very unwilling to 

 admit that their " Purple Clover" can be a variety pro- 

 duced by cultivation, as is generally supposed by bota- 

 nists, seeing that the former is perennial, while the latter 

 is biennial only, and their agricultural properties are very 

 different. This, however, is very good for cattle, and 

 very noisome to witches. And, in the days when there 

 were witches in the land, the leaf was worn by knight and 

 by peasant, as a potent charm against their wiles ; and we 

 can even yet trace this belief of its magic virtue in some 

 not unobserved customs. Hast thou never sought, and 

 deemed thyself fortunate in finding a four-leaved clover ? 



" But woe to the wight who meets the green knight 



Except on his faulchion arm 

 Spell proof he bear, like the brave St Clair, 

 The holy Trefoil's charm ; 



For then shall fly his gifted eye 



Delusions false and dim ; 

 And each unbless'd shade shall stand pourtray'd 



In ghostly form and limb." 



4. T. medium, spikes lax ; stems zigzag and branching ; petals 

 nearly equal ; calyx smooth, 2 upper teeth rather the shortest ; 

 stipulas tapering, converging. Zigzag Trefoil 



Hab. In deans. Longridge dean. July. If. 



The characters which best distinguish this from the preced- 

 ing, seem to be the shape of the stipulas, and the smooth 

 calyx. The heads of flowers are also somewhat globular, 

 concave on the top, and of a finer purple. The character 

 afforded by the comparative length of the lower tooth of 

 the calyx, and of the tube of the corolla, adopted by WILL- 

 DENOW, and borrowed by HOOKER and GREVILLE, is not 

 to be depended upon, since in this we find the tooth some- 

 times much shorter than the tube, while in the cultivated 

 clover it is often equal to it in length. 



