30 



WEEDS AND USEFUL PLANTS. 



are popularly known as Buttercups, and in some localities are so abun- 

 dant in meadows, as to appear at a distance like an unbroken slieet of 

 golden yellow. On account of their very acrid juice, cattle do not eat 

 them in their fresh state, but when cut with the grass and dried, the 

 acridity is dissipated, and they become apparently quite innocuous. 

 Before the introduction of Spanish Flies, these and other species were 

 used to produce blisters ; being uncertain in their operation, they are 

 now seldom employed. About a dozen other species are to be found in 

 the woodlands and meadows, and a few aquatic ones in streams and 

 ponds. The only one of these which assumes the character of a weed 

 at the north is E-.repens, L., the long stems of which are usually pros- 

 trate and rooting at the joints ; it has large bright flowers, and is some- 

 times common in wet meadows. R. muricatus, L., is an introduced 

 species, found in the fields in Virginia and southward. It has roundish, 

 mostly 3-lobed leaves, and the akenes beset with spiny tubercles or 

 bristles. Both R. bulbosus and R. acris frequently become perfectly 

 double by the transformation of their organs of fructification into petals, 

 and are frequently cultivated in gardens. In the ^(mb\Q R. bulbosus, 

 the flower is proliferous, the receptacle producing, instead of a head of 

 pistils, a bud which developes as the old flower falls away ; this is 

 repeated several times in succession. 



4. CAL'THA, L. Maesh Marigold. 



[Greek, Kalathos, a goblet ; from the cup-like form of the flower.] 



Sepals 4-10. Petals none. Pistils 5-10, without styles, forming in 

 fruit many-seeded, compressed, spreading pods. Smooth perennials, with 

 large round or heart-shaped entire leaves. 



1. C. palus'tris, L. Stem nearly erect, hollow, furrowed ; leaves round, 

 heart-shaped or kidney-shaped, often wider than long, crenate or nearly 

 entire. 



Marsh Oaltha. Marsh Marigold. Cowslip. 



Sfem 5-10 inches high, succulent, sometimes branched. Radical leaves on petioles 3- 

 6, and finally often 12-15 inches long. Flowers an inch or more in diameter, few, some- 

 what corvmhose, bright yellow. 



Swamps and wet meadows ; common at the north. April. 



Ohs. This plant has considerable acridity when fresh, but heat de- 

 stroys it ; it is much used as a pot herb or " greens " in early spring. In 

 New England its popular name is Cowslips (or corrupted into cows 

 lops"). It has no botanical relation to the Cowslip nor to the Marigold. 



5. COP'TIS, Salisb. Goldthread. 



[Greek, Kopto, to cut ; on account of its divided leaves.] 



Calyx of 5 - 7 petal-like, deciduous sepals. Petals as many as the sepals, 

 small, thickened, and hollow at the apex. Stamens 15-30, shorter than 

 the sepals. Pistils 3-7, each upon a short stalk, which lengthens as the 



